It is extremely unrealistic to think that anyone will be travelllng for pleasure anywhere until a vaccine has been widely distributed and has shown to create herd immunity.
What is likely to happen is that people will be able to travel with the EU for permanent reasons, e.g. relocation, if they are willing to do a 14 quarantine, and some people will be able to travel for work but that’s about it.
If there is an immunity test and it is shown that immunity lasts, people with immunity passports may be able to travel more, but that’s a lot of ifs .