I'm thinking they won't be filming before at LEAST fall 2021, and even then it will be only in countries where more than half the population is vaccinated, and the whole cast and crew as well.
If they continue after the 3 legs that they already have, I'm expecting some legs in countries that are more safe (Australia and New Zealand would work well now, but would depend of the restriction coming in. Two legs in Canada would work also, like one in Québec city to be a bit foreign, and maybe one in Atlantic Canada or Vancouver).