I'm in the same boat, looking to cut my ISP as I can't afford to pay anymore. I got a coupla businesses around and I'm looking into mooching off them.
thought about getting something that can try the usual passwords ('12345678' and the like) but I can't run Kali and friends because the only wifi card I got in my laptop doesn't support monitoring mode. besides, that would be crossing the line, I really don't wanna "hack" people, just try to use their guest networks.
if that doesn't work out, then I'll use my laptop on public wifi. get out there a couple times a week and get what I need in batches and then process them when I get home, sorta like in the uucp days of dial-up internet in the early 90s.