I don't necessarily agree that "nobody should have X until everyone has Y" is a workable general rule; no family should have two cars until everyone has one; no family should have two jobs until everyone has one.
The second home is already slightly tax disadvantaged compared to the primary residence, perhaps it should be "punished" more.
Seriously, a "winter escape"? Literally noone needs that. Literally noone should have that until everybody's basic needs are met.
Which won't happen with all these "storage unit" houses there are.