If you have the option to host physical hardware from your friend's house, I'd go that route for the whole thing. Set it up so they can access your media server locally, maybe even immich, and VPN in for everything yourself, that way you don't have to expose ports, except the wireguard port. Don't acquire new content from their network unless you do it behind a good VPN with a killswitch and they know and are OK with what you're doing.

I would personally rather have my documents, photos and media collection on a computer a friend has physical custody of than in the cloud, but that's on you and your friend. I prefer to host vaultwarden and a notification server, in my case, gotify, on the cheapest vps I could find, which was about 12 bucks a year last I checked.

I'd also set up a tor hidden service for ssh, just so you have another way in, in case something comes up. Or you could get a cheap cellular modem and a yearly Sim card. In the US, red pocket is a good choice, with a limited option available for less than 50 bucks a year. You never know when their ISP is going to do something weird, and you'll be able to figure it out a lot easier if you have a reliable way into your server.

You should probably think about backups too. You can obviously do a backup before you go, but you're going to want to back up at least your new photos while you're gone. I'd suggest looking at koofr lifetime storage plans, as they're pretty cheap for the size.