Get better cooling. Wife and kids deserve an AC in these inhumanely hot times.
Downclock the system to have it run cooler for now.
Get a properly monitored backup system which either sends you and wife an email automatically sorted into a separate mail folder via IMAP sieve rules, or has a dashboard with last backup time and diff size which has triggers if the backup is older than 3 days or diff size is larger than 10% of total storage.
I recommend the LGM stack (Loki, Grafana, Mimir).
Document everything and make it as easy to retrieve the plain files as possible in case you die.