I do not have much knowledge about the current concerns regarding Tether as to whether they will have an effect on it as a stable coin or not. If I were in your shoes then I would simply switch to fiat and Bitcoin. Bitcoin may equally not be stable but it has always been a good choice.
Bitcoin is indeed the main choice for investing. but I personally still hold tether for long-term investment. the issue that happened did not make me panic, and it would remain in the analysis that I had planned
The issue that has happened or yet to happen? because I have not seen much issue around and the one that will create the big panic is yet to be decided in court and it is better you be on a safe side, because if the whole thing turn around to be against them, you might not be fast enough to take all your investment before they shut down the system or lock the system from withdrawal.
Look at when Binance was hacked, what they did first was to lock withdrawal and many people that were going to move their funds out of panic could not do so, but they were just lucky that Binance overcame the challenge and came out stronger, but bitfiniex might not survive this.