I don’t really have a good answer, but I really don’t think the fold is the way to go. You say it’s not much of an upgrade over the 7, which is one way to look at it. The other way is that both are 7th gen devices, and as such, it isn’t an upgrade at all.
Personally, phone size is really a non-factor, and while I used to think my 8 Pro was massive, now I’m just used to it.