Yeah, I guess the plan would be (if we decide to use an old labtop) to have a similar backup system to my home server, so one daily incremental backup with something like borgbackup to a newly bought external hard drive and automated updates using watchtower (I heard major nextcloud upgrades can be tricky though, so I an not shure if it would be a good idea to automate those). I guess it would still suck if the laptop unexpectedly failed and we would have to scramble to find new hardware though, how long would you expect an old laptop to last as a server?

Yeah, I totally get what you mean, I am kind of expecting that aswell, but at least I know, that other scouts groups in the area already have a nextcloud and it is actively beeing used, so I have some hopes in that regard. But yeah, getting them to use something like Matrix is probably pretty unrealistic.