Am enjoying the varying opinions!
To respond:
I can't go on spa break unless I go on my own all my girlfriends have their own small DC, so they will not be going anywhere.
DH would happily take the DC somewhere by himself for a few days if I wanted him to.
If it makes a difference (and it probably doesn't) the baby is his idea, I was perfectly happy with 2 DC.
I have easy pregnancies, would of course manage, would just be even more tiring than normal. Taking days off work not an option its a busy time of year can't take time off then, and it might not help as would still have to get them out to school etc.
If it makes a difference he has never wanted to do anything like this before, for example would have been perfectly happy about it last Feb when I wasn't pregnant, was about to leave my old job (hence work not stressful) and we had a full time nanny as DS wasn't at nursery. He only wants to go as his BIL has suggested it. He is not a good skier, he just thought a few days away sounded nice.
He wants a break as he is not especially happy a work, he knows not possible after the baby comes.
He is generally helpful, so I should just say I'll manage.