Small batteries for individual devices instead of house battery?

We have a vacation home in Palm Springs that we also rent out. Power outages are very common, though usually not more than 8 hours. We have solar but no batteries or backup generator.

We’d like to get some sort of power wall but that’s expensive and I was thinking in the meantime of getting a few small power stations, one for each bedroom to run fans, phone chargers, lamps, etc. And one for the modem and router.

Any suggestions on what to get for such use? I’m thinking 300-500wh, something like this:

https://www.amazon.com/BLUETTI-Portable-Pure-Sine-Generator-Emergency/dp/B0B71G2KSQ/

For the bedrooms. Something smaller for the modem/router.

I’d appreciate any suggestions if anyone has any experience in this area. Thanks!