It would be an absolute bear to try to get rank & file JWs to go back to normal door to door work after pandemic restrictions end or are greatly reduced. The longer it goes on, the harder it will be to restart.
I suspect that door to door will be greatly de-emphasized and a lot more "cart witnessing" will be introduced, even in areas where it would seem really weird. I suspect any remaining "door to door" will be more like "farm to farm" out in the rurals, and most urban and suburban JWs (probably over 90% of the whole JW population anyway) will be "on the carts".
Most JWs I know just love the carts. You get to "count time", you are "visible in the ministry", but rarely have to actually speak to anyone. If anyone shows interest, you have a great experience to tell. If anyone gives you a hard time, the cart overseer (yes there are cart overseers) just packs up and moves to a different location.
So that's my prediction: in the future, a major emphasis on cart witnessing, and the vast majority of JWs won't do door to door ever again.