If I had $130,000,000 worth of assets seating in my wallet, I would not cash out all of it to fiat to avoid attracting unnecessary attention to myself. I would leave most of it in crypto and only convert 1% of it to fiat.

I think there's a limit to the amount of money your account can receive from exchange but this may vary in different countries. In Nigeria, the maximum amount you can receive in a day on Binance exchange is N18 Million and you must be an active trader.

You've said it yourself that according to FDIC insurance, an account can only hold $250k, so what do you think will happen when someone who's account balance is $3k, sudden receives $250k in four hundred different accounts? Your account would be frozen and you would be called upon by the authorites to explain the source of your wealth.

I would never let that happen to me, nor do I think anyone else would. Nobody has $5,000 and waits until it becomes $130,000,000 without cashing out anything first. The normal thing is to cash out little by little as the ball gets bigger and bigger. But even if you had partially withdrawn along the way and ended up with a huge sum anyway, or even in the scenario you pose, you are foolish if you plan to do it on your own or with advice from a forum.

Well, in that case one of the best option you can do is to get it OTCd in any banks that accepts bitcoin or any crypto exchange if you want to cash it out all at once, just to make sure your account is gonna be safe from being froze.
There's almost no way you can have it all cashed out using online transactions, or using the most basic trading in any exchange or any bank transfer for that huge amount of money.
IRS plus some transaction fees, I'm not sure how much is gonna be left after all those are taken out. So, you're not getting the whole $100m.

Why would anyone want to cash out that much money? What kind of purpose can that be used for?
I can't really imagine a situation like that, but I think that such a huge amount of money calls for an OTC deal. Just after googling a bit, I can see that some major companies, including Coinbase, have OTC desks for big cashouts, so I would probably contact one of those, learn how these things work and do it like that. This way I wouldn't negatively impact the market, I wouldn't have to wait forever for my deal to be done, and I'd establish useful professional connections, I guess.
Needless to say, I'm sure I'd have to pay a sell tax on that money, which I should, considering how much I own in that hypothetical situation.

It's very simple to do, just know that you don't have to necessarily move the whole money at once, you can do it instalmentally and also if you're exchanging them with an exchange, then try to avoid the same bulkiness of sending or withdrawal at ones, you can also make use of a decentralized no kyc exchange and make use of the p2p network, there's whale alert system that also notifies of any giant move of currency, so in every decision you will be taking, don't just make it suspicious by making huge transaction that could be alarming.

I would not even consider converting that amount of coins in one transaction. I would open several accounts at different Crypto currency exchanges and then transfer some coins to all of them. I will then convert smaller amounts and deposit it into several different Bank accounts that are linked to those exchanges.

The Banks already flag transactions at a much lower amount (I think something like $10 000) .. so the Tax authorities will know, even if you do this with small amounts.  

To be honest, none of us has ever owned or currently owns such a large amount of money, so answering this question is really not easy. I also agree with everyone's solutions such as splitting the withdrawal amount even though it will take a lot of time, or using a company account...But it's all just our thoughts and none of us have any experience with it. Therefore, it is difficult to know the effectiveness of these solutions.

In my opinion, we should focus on accumulating bitcoins now, and if we have the opportunity to own a large amount of bitcoins in the future, we will definitely have a solution for that.

In actuality, such a huge sum cannot be casually released. Perhaps using several exchanges will be required if I have such substantial assets; in that case, I would just have a daily release cap. To be completely honest, if I spend that much, it will probably take a few months.

Because there is a restriction on the withdrawal in the local wallet where I transfer money from cryptocurrencies in our nation, our local wallet may naturally ask me here since I withdraw over P2P every day.

Then why the question at all? Every country has its own laws, so if you acquired that Bitcoin in a legal way, then you don't have to worry about anything, including taxes, banks or exchange offices.

In case I have such a large amount of BTC, I would never sell it in a way to cause a lot of attention, but I would do it in a way to try to negotiate the sale with to some of the CEXs that I would then visit in person and sell through their OTC. Before that, I would open bank accounts in some reputable banks in Switzerland, where I would also rent safes and store some of the cash in them.

In fact, there are countless possibilities and it is true that it is not a problem to sell that much BTC even if you don't want to go directly through CEX, but for most it will never be a "problem" because they will not even have 10 BTC, let alone the thousands that we are talking about hypothetically here.

Besides, why sell everything when there are so many ways to use Bitcoin as a currency around the world - booking hotels, buying plane tickets, paying in restaurants and on thousands of online sites that sell various goods and services.