We also have a hot tub and we're in New England. We were worried about a multi-day outage resulting in the tub freezing in the winter. A low probability event, but one that was conceivable.
Both the fridge and the hot tub problems can indeed be resolved with something less than our 16kW generac. The hot tub really just needs a small space heater to be put inside the cabinet to prevent the pipes from freezing. And as you say, fridges don't use much power. So powering those two things (and our upright freezer) would need a pretty small power source.
So absolutely, we overdid it a little. But it's super nice having it kick on when we get an outage. Otherwise I'll be playing the, "is it really worth going out in the snow, lugging out a generator and getting it running if the outage is just an hour?" game. There's also the issue of maintenance, which I'm... not greatest at to be honest. (I have a 2 year old at home and time is just absolutely slipping by. It's hard enough to keep up with normal chores.) The standby generator does a weekly test, so we know whether it's actually working or not.
Yeah, definitely a bit of a luxury, but worth it for us. :-)
I am not an expert on generators though. If you're not looking to maintain it yourself, I'd say the most important bit is going with people that have good customer service. Which depends on your area. Might be Generac, might be Kohler.
See also: https://old.reddit.com/r/Generator/
Also, a deep freeze that is the top loading style is best for preventing spoilage, especially if you keep all the available space full of bags or bottles of water.
I also have a makeshift "whole home" backup generator, 11.5kW/9.5kW peak on gas/propane, but only because i have a well, and the pump draws something like 4.5kW when running. The extra headroom allows me to run my 5 ton HVAC and have running water and lights and everything.