YANBU, as Trix already pointed out on the previous page, your DH has to fly business class, no way round that, he works hard. Don't forget he has already deferred his bonus as well, what else do you expect him to do? Get real, give the man a break.
However, you don't work hard, so why can't you sit with the kids? Or do you also work hard and have you also deferred your bonus? In that case, by all means go business class as well.
As far as the kids go, I doubt they work hard and they certainly haven't deferred their bonus, so there is not reason that they should fly business class. Also, they are lucky you allow them to fly premium. Actually, they are very lucky you fly them full stop. Have they really deserved a Holiday? Can't you park them somewhere? They are the right age to send on a residential Camp somewhere? What about Grandparents, other family, friends, can't they look after them, so you can have some quality time with your DH, because don't forget he is a hard working man, probably in his office all hours of the week, 7 days a week, so it is unlikely that you get much quality time.
Hope you have a nice Holiday with or without kids. Don't feel guilty about it. You got what you got because you work hard and deserve it. 