You can treat illnesses naturally with tea, orange juice and naps, medicine isn't the only option. TBH I always felt like medicine in this game is no different than cheating the moodlet away so you can always just cheat and deduct the funds from the medicine cost, there's really no difference. I wish it was a more organic healing like teas and naps where you need to take multiple doses of medicine until full recovery, with the advantage that popping a bottle is way faster than drinking and napping. It would've been more realistic and fun in my opinion, but anyway.
Also I think the new Off-The-Grid trait works the same way a normal lot does when you stop paying the bills so we can already test which objects works or not. I know there's a system like that already because I did it a long time ago and candles and such still worked for me!