I don't think exclusion will work it won't be long til people get fed up with zero travel (especially to family in England, NI, Wales).
NZ has been brilliant I look at friends in NZ and they have a normal life pretty much, gigs, bars, holidays etc. But NZ are also used to being isolated and it being expensive to fly outside NZ. Plus the difference between North and South Islands means it very much feels like a holiday they can fly to go skiing in the south or have a beach holiday in the far North!
Friends who have visited from NZ found Europe astounding as they can travel quickly and that's the difference.
It's a very interesting and difficult question I don't see how you can even get elimination without then still restricting travel between Scotland and England (as you can garentee they won't do the same!).
My DH and I are from England would the govt really say that thousands of families shouldn't be able to see each other for any longer then is necessary potentially all year or longer? I certainly wouldn't follow that (and I have followed every bloody rule to the letter due to DH job). It's too much of a push for my son to miss out on his grandparents completely whilst they are still on this earth!