SSH connections frequently disconnected when using a mobile hotspot for internet access

My ssh sessions are frequently disconnected when I use a provider that offers internet service via cellphone towers. They seem to "freeze" and stop responding to anything I've typed, but sometimes don't give an actual disconnect message until several minutes after they have frozen. I'm answering my own question in "Q&A style" below - this is a problem I've spent the last year trying to work around, and I wanted to consolidate and share all of the solutions I've found so far. (Feel free to add your own answers too if you have other solutions I haven't found yet!)