+1 for Unifi Protect. Their hardware may be a bit pricey, but it doesn’t require any cloud/Internet connection and the app/interface is excellent.

I haven’t tried the 3rd party cam support, but I don’t think the price for the cameras is too outlandish for what they are and how well they’re built.

Iirc the Unifi Protect software can be self-hosted now too.

If you aren’t too sensitive to a bit of input lag, you could keep your laptop around and stream the more demanding games over steam link. Streaming these demanding games will also significantly increase battery life, but I don’t think it will work away from home. Most games run quite well if you drop the settings (outside of those using intrusive anticheat), and it runs lighter games very well.