BIL is a support bubble for a family member who lives alone around 100miles from BIL. They have no family nearer and visit for roughly a week ever month to have some company.
The family member is now tier 4 and BIL tier 2, the family member is scared to get BIL in trouble by visiting on Christmas day. They do have friends nearby in their tier but then surely that seems to negate the original bubble? Albeit more logical! Everyone has isolated for 10 days so far apart from walks so the risk is low as I see it but I've been asked an opinion on whats right and I'm not actually sure!
I'm not happy to state the person should be own on Christmas day though, that seems awful!