I don’t use Nextcloud calendars or address books. But I assume they are included in regular backups.
I pay about 50€ for all absolute overkill Hetzner dedicated server (128gb of RAM).
I live in two different flats in different cities because of personal circumstances.
I assume you basically want protection against disasters, but not high uptime.
(E.g. you likely can live with a week of unavailability if after a week you can recover the data.)
The key is about proper backups. For example, my Nextcloud server is running in a datacenter. Every night I replicate the data to a computer running at home. Every week I run a backup to a USB drive that I keep in a third location. Every month I run a backup to a USB drive on the computer I mentioned at home.
So I could lose two locations and still have my data.
There is much written about backup strategies, for example https://en.wikipedia.org/wiki/3-2-1_backup_rule … Just start with your configuration, think what can go wrong and what would happen, and add redundancy until you are OK with the risks.
I did some testing with it, because I believe more people should be able to self-host.
I like how it is implemented. It has good support for email. Many apps support SSO.
The critical part to me is how up-to-date applications are. I started a small project to automate version tracking, check out:
https://alexpdp7.github.io/selfhostwatch/app/nextcloud.html
; so for example, the YunoHost Nextcloud app does not lag much behind upstream. My intention with this is to let people see that they have been updating Nextcloud dilligently for two years; they might pull the plug tomorrow, but it’s a good track record.
(I’d like to add scrapers to other projects similar to YunoHost. My ultimate goal would be to be able to choose a list of apps you’d like to self-host, and see which projects like YunoHost carry the applications you want, and compare how they track updates.)
IMHO, it really depends on the specific services you want to run. I guess you are most familiar with Docker and everything that you want to run has a first-class-citizen Docker container for it. It also depends on whether the services you want to run are suitable for Internet exposure or not (and how comfortable you are with the convenience tradeoff).
LXC is very different. Although you can run Docker nested within LXC, you gotta be careful because IIRC, there are setups that used to not work so well (maybe it works better now, but Docker nested within LXC on a ZFS file system used to be a problem).
I like that Proxmox + LXC + ZFS means that it’s all ZFS file systems, which gives you a ton of flexibility; if you have VMs and volumes, you need to assign sizes to them, resize if needed, etc.; with ZFS file systems you can set quotas, but changing them is much less fuss. But that would likely require much more effort for you. This is what I use, but I think it’s not for everyone.