Speaking from Ireland. - Car traffic will be only slightly less than 2019 levels, despite rolling lockdowns all year. - Brexit will start to be noticed on supermarket shelves. - The built-up stresses of 2020/2021 will turn some relatively minor issue into a genuine political crisis, in a straw-that-broke-the-camel's-back situation. It might bring down the government.
Do you think Brexit reaching a conclusion could spur reunification between the Republic of Ireland and Northern Ireland (a “United Ireland”)?
If Northern Ireland is following the Republic of Ireland/EU commercial regulatory framework, and not the rest of the UK's as that quickly diverges, there will be a new pragmatic argument for Northern Ireland to leave the UK.
I'd give it at least 5 years, though.