If it works for you with your pick-up times so that you have enough time after nap to change them and give them snack, then why not? I think the thing I would be concerned about though is that they would melt down and be way overtired by the time naptime comes around. The later sleeping might also effect their bedtime at home at night, so you might want to just change it to 1-3 so it isn't such a drastic change.