The only travel the Feds can probably restrict legally would be airline flights.
Given this new faux administration, since when are they concerned with legalities?
This is a pandemic, c’mon man.
Since when do Democraps care about legalities?
They can put National Guard troops on the Florida/Georgia border blocking the interstate highways.
They could be there a couple of weeks until the court challenges work their way to the USSC.
Then considering how much leeway the court decides a President has during a state of emergency, it could go either way.