Brilliant
For real, if you paid actual medium-to-high money or points for your travel and can get a refund, you should.
As far as rebooking cheap, depends on if you have down time that you'd do nothing else and if this is the one time you'd ever visit the Bay and Seattle. It'd be a weird experience for your lone time, if so. At least in Seattle, almost every tourist thing is shut down. There'd still be natural places to check out and bars/restaurants to PAK at. The latter would be especially welcoming for your business, as every day more and more are closing temporarily or permanently because there's not enough people out. I'd be directing you to my favorite establishments and to drink and eat heavily there.
I think the Bay has a lot of the same attendance restrictions/guidance, but not sure. It'll be like that everywhere shortly.
If you had in mind taking selfies on top of the space needle, etc., there wouldn't be any of that. You'd just be drinking a lot, seeing some nature views, and not getting sick.