The border will certainly reopen before complete vaccination is reached. Once the numbers start dropping drastically showing the Covid is struggling to spread as hosts become fewer, things will start to change. Reality is by then the border will have been closed for over a year and businesses and the public will start to scream to get things on the path to normalcy once the stats start showing a shift.
Reality is Covid19 is going to be endemic, like the flu. Once the spread starts to slow and the high risk categories are vaccinated and now protected (something that should happen by late spring or early summer on both sides of the border) we'll see restrictions start to loosen, particularly once the warm weather arrives and people are back outside again.
I'd still be careful about where I choose to travel (IE, Florida is off the menu) but some of the more sane US states, well, I'd go...with precautions.