My best guess is Zoom for the "midweek" meetings and "in person" on the weekends.
It's going to be a bear for them to try to get the R&F motivated to get back to door to door though. It's well over a year since it's been done and I'd bet it wouldn't start up again for at least another year.
After 2-3 years of writing letters in your pajamas on Saturday morning, how are they going to get folks to wake up early, get dressed, travel to the KH, walk around in extreme heat or cold, and knock on the doors of houses that are 90% empty?
There will always be the zealots and the ones who will grudgingly do so out of fear of losing their meager "privileges", but for Joe & Suzy Average Publisher, who have no such incentive? It's going to be harder than they (the GB) can imagine.