A fine tale, ending much to my amazement (and admiration) with further progress on stuff in your mom's house!
And while I can eventually change a tube, and maybe even get some air in it if I can remember how to use the little compressed air canister(s) I carry, the odds of even starting the process in a downpour are pretty close to nil.
It was only raining a little when I started fixing the flat. Had I had a proper pump, I would have made it home, though the riding would probably have gotten pretty miserable. I was lucky to be so close to Mom's house, and once I was there, well, I had to do something to kill time. (Alan was concerned that I'd get the tire fixed and then try to ride home in the dark, which, to be honest, wasn't out of the question in my mind, because I could have grabbed the flashlight from the kitchen.) I got a lot of practice fixing flats in the summer of '83, riding from Danbury to San Francisco, when we never had an intact tube, and when either of us got a flat we'd start removing the wheel while the other would set about patching a tube.
I had to patch a flat on my mountain bike in Penwood some years ago, in gathering dusk and a giant cloud of mosquitoes. I remember them looking like fur on my arm. But got it done and rode out of there in some pretty dark conditions.