

Check out SFTPGo for backups.
Also, I wouldn’t open any ports on your parents network other than for something like wireguard
I especially wouldn’t expose home assistant to the internet, as it’s quite lax on the security front.
As for RAM, 8gig will be more than enough unless they have an ungodly amount of smart devices. I’d stay away from a raspberry pi when deploying to an offsite location, as they’re not very reliable long term. Get a NUC or something similar. I just picked up a gmktec n150/12gig soldered on amazon for like $130
I opt for the happy middle route- I use gadgetbridge on a huawei watch fit 3 so I still get good stats/UX but I’m not reporting back to anyone.
I am eyeing the new pebble watches, though