"I'll whack in some manual VACUUM cron jobs during low load maintenance hours and hope that keeps the worst of the problem away, that's what random forum posts on the Internet say to do". -> "oh my, why did my DB just do an emergency shutdown?"
This one doesn't make much sense to me, unless they mucked around with autovacuum_freeze_max_age as well as turning autovacuum itself off (common practice?). With the default setting of autovacuum_freeze_max_age, if it can't complete the anti-wraparound before emergency shutdown with autovac off, it probably would not have completed it with autovac on, either.
