We've gone en masse a few times.... When all of the sibs/partners/kids are there, we're 12 in total, so we've gotten some lovely villas with pools between us, for example. We've also done it where my folks (who are sprightly, fairly recent retirees, with a campervan) have toddled off to Spain or France with the van, and then some or all of us have flown off to meet them somewhere, and stay in a hotel/holiday apartment.
We totally surprised my Dad when he was 70, as we all 'couldn't get time off work/it's not an easy time to take kids out of school', and then flew to Italy to surprise him - all 10 of us! We needed my Mum's help to co-ordinate that one, though - as he's fond of changing their plans... the beauty of a campervan!
However, without our own space, we find 3 days is pretty much our limit! The parents are retired, so like some down time; both my siblings have partners and kids - of different ages - so need activities; and I'm the childless maiden aunt, who pretty much goes along with most things - but I do have a physical disability which makes it a wee bit tricky sometimes.
Anyway, I suppose what I'm trying to say is that we try very hard to get something to suit everyone, but SHOCK HORROR, we do actually mainly like each other, and get along, so enjoy a bit of time together - and if it's sunny, with fun things to do, and nice food, all the better.
The only time we didn't holiday with the family would be when each of us were in our late teens to later 20s, where going away with friends/boyfriends was more entertaining. Now we would all have a main holiday on our own/in own smaller groups/with friends, and the family trip as well. We're hoping for South of France this year. 