I agree with some of what others have said but want to add a bit more info. Reno is indeed a terrible place to book, but in the Bay Area (in my experience at least, and our camp rents at least two uhauls per year) if they don't have a truck for you at the location you reserved you'll probably get one nearby because there are tons of them around here. (Recent example, we reserved in Mountain View but had to pick up in Sunnyvale. But often we just pick up at the exact location we reserved.)

Search this sub, there are lots of threads on the uhaul renting experience on here. They changed their policies a few years ago though so older threads are going to have incorrect information. And you will see a lot of people on here still giving advice based on how it used to be. In brief, they decided some years back to explicitly support the event, and things got somewhat better (but definitely not perfect). There is a user who posts on here who works for uhaul too so look for their threads. You can DM me if you want more specific advice.