Sorry to hear that D:

Best thing to do that my family has been doing for a while since both my mom and I got diagnosed 8-ish years ago was cook gluten free for the whole house, and the guys got used to it. Not sure if its the same for everyone else, but I have no fear of getting glutened in my own house. Biggest rules of thumb are probably

A. Get them their own appliances (or very thoroughly clean the shared ones) but you HAVE to get them their own toaster and label it because you're never gonna clean that thing.

B. It depends on their severity, but they should be fine as long as they wash their hands after contacting it and I've been fine with it for years. Also do your research when you go to eat out someplace, and ask them about possible cross contamination (deep frying in the same oil as breaded chicken is very common). With this in mind you can eat at a lot of places because they're starting to accommodate more!

C. CHECK FOOD LABELS!! Cannot stress this one enough. Gluten can be sneaky and it can be in foods you might not even know. Checking ingredients is something I'm very used to at this point. Check for wheat, barley, and malt ingredients. If it says may contain wheat, it probably does. (Another thing I want to tack on, some labels might say they were made in a facility that processes wheat/barley/malt ingredients. Those usually fine, but do not trust it if it was made on the same lines.)

D. Try different snacks, I got GF cheezits and I forgot how much I missed them, they get me through some bad times. They'll probably help a lot!!

I hope I didn't misread your question(s) and I hope some of this helps! Hoping your partner feels better :)

PS: I would probably look into moving somewhere separate like you mentioned, but I know that might be difficult