It is possible for a government to "clog" the bitcoin network for months with frivolous transactions with high fees because they're able to print infinite money?
It is theoretically possible but in practice it will face many problems. You are talking about an attack that will cost money. It requires the government to dedicate part of its budget to performing this attack!
There will be a backlash from the people of that country who will see their money wasted on an attack while a lot of problems in that country exist (eg. health care).
There will also be a global backlash when bitcoiners see a rogue government is carrying out an attack on the money they use!
That's not to mention the fiat being printed causes inflation in that country... which would bring more backlash...
the price of bitcoin could theoretically be 2 million/coin at that point and no one would be able to move any funds.
That makes no sense! Why would bitcoin price go up if a government is attacking it making it too expensive to use? If anything price could drop.
State currency 1:1 backed by bitcoin can be used for global adoption.
I don't understand how your two opening lines led to this, you forgot to create that link.
In any case, if it is a dedicated currency created to only be 1:1 backed by bitcoin while the government keeps its fiat and continues printing it, that currency is going to be considered an utterly useless shitcoin because bitcoin already exists and just because someone prints something new and says it is backed by bitcoin it doesn't give it any kind of value or utility.
If you are talking about government giving up unlimited supply fiat and come up with a new currency completely backed by bitcoin, then that is impossible. They will not do it. The economy is not designed that way either, unfortunately...
The beauty of living in the west or any high credit nation is that the economy itself is pretty safe long term
I think 2008 catastrophe already taught us that not only it is not safe but it is extremely fragile and can easily and catastrophically collapse in a blinking of an eye.