Matrix chat and video conferencing (nginx, Synapse, MAS, Livekit, coturn, Postgres)
Prosody elsewhere for failover if international links go down
Nextcloud
offsite backups for important data, not the whole OS (rsync)
QR scanner on a webpage, for transferring complex passwords locally
Syncthing
Offsite monitoring (Prometheus, Grafana, AlertManager) - amusingly, on an old ex-Android phone running PostmarketOS (a variant of Alpine). Eats less than a watt of power.
Wireguard to hook up the monitoring with minimum fuss
