Like you said, "monthly rental are not really a thing". It's hard to find without being there. I usually look on the internet (mostly France for now, I use leboncoin.fr) but it's time consuming. I always need to explain to people why I do (they don't really understand why I'm looking for a month), I need to negociate the price, be sure there is a good internet, etc.

I'm thinking of an Airbnb just for this: rental for nomads with monthly rates (and other things that matters like a good connection). I'd love it for myself at least, but I guess it could probably be useful to other nomads.