Maybe say you didn't realize the negative impact it was going to have on the toddlers who are still napping at the time in which you need to leave and that it's difficult to take them from their beds right to the car without a chance to wake up.
The kids here sleep right till 3 or 3:15 so I wouldn't want to yank them from bed to take them out in the cold, plus if you put them down earlier it really shortens your morning ... You'd have to serve lunch at 10:45 to have them in bed by 11:30 so they could have a good 2.5 hour nap in order for them to be up and ready to go .... Yikes