Plus, as a solo, you get to determine whether that standby line is worth your time. Sometimes with other people, the collective opinion may be to skip a line with an expected wait time of an hour. But if you're there solo, and you don't mind the wait, you can do it. I agree that it can be easier to find random FP+ for one person than for more. But it can still be difficult to get a few of them. Personally, if you can't get Frozen as a FP, I would get Soarin (I've never had an issue getting a solo FP for Soarin even the night before) and then hit Frozen first thing at rope drop. You'll still have a wait, but not as bad as it can be later. Or, you can try Frozen last thing before park closure, if you don't mind missing Illuminations (and if it hasn't broken down). I change around a lot of FP+ the day before, and sometimes the day of if it's early in the day, and since I'm not a thrill ride fan either, I don't usually have much trouble getting what I want.
If you want to do the new Pandora rides, I would recommend getting FP for those if possible. If you are only doing AK one day, you'll have to pick one or the other, but FoP does have a single rider line, which may help you out.