I think it's fair that DP takes the kids out to some of the activities by himself. After all, you do.

I think DP might prefer lates because this way he's having more of the domestic fun and less of the domestic pain and so why not? I think it's fair for DP to put more effort into housework, by rearranging the way he does things when he's working lates. For example could some of the bathing of children be shifted to the morning (not sure, some kids are grubbier than others) - this was something I did with DD2 when DH was away as it took the pressure off in the evenings.
I think the key to workabilty here is finding a new routine that is manageable for both of you.