One important difference re Insurance…
The first time I was involved in a house-fire (totally destroyed)… it was for a Principal Residence and the Insurance paid firstly for rental of a gite for immediate occupation … and then for a mobile home put on-site for the folk to live in while their house was being rebuilt.
I can’t see that happening for a maison secondaire…
I’m just advising folk to make sure they’ve updated their information… as and when necessary.