If Biden gets inaugurated, President Trump and his family will need to be somewhere that doesn’t have an extradition treaty with the US, along a lot of liquid assets.
Democrats (and GOP-E) are vindictive as Hell, and will try to imprison him, persecute his family, and destroy his wealth.
I think the President's life will be in danger the minute Biden takes his hand off "How to do partial birth abortions" or whatever his holy book happens to be.
Not sure he'd be safer in the UK, though.