When I did kindergarten I always had them go in the afternoon for the reasons you are thinking. We did our own things in the morning and then they went to school and little ones went for naps. No having to entertain the big kids.

It does mean shifting your schedule. You eat early and then take them to school - one thing I did do the last few years was arranged with another parent that always walked their own child was to hand off the kindergarten child to her - with the mom's blessing - and then immediately leave to come home. So kids were in bed pretty much on time. (school was from 1 - 3:15) I know they have staggered the times now so that will be an issue. I could have the kids up by 2:45 changed and be back to the school for 3:15. We had snack once we got home.

I do not regret not taking JK/SK kids because of the trip - no it isn't fair to the little ones and while they don't see a problem now you may have to deal with anger from them come next year when it is raining or -35 and still have to go to the school and they dont' want their child to go out and start threatening to pull them then what are you going to do.

If you are not able to drive them and do not have an enclosed means - there is something called a turtlebus a friend of mine had - actually had it for sale for ages when she closed her daycare but it only sat 4 as she figured the school kid would be walking. Very expensive and imported but if this is just the JK year and you plan to offer this service in the future you might want to consider something like that the keeps the little ones out of the elements.

This comes down to one of those does the needs of the one outweigh the needs of the many - I have chosen the once you start school you move on - and often the younger child stays with me - many schools have half day care available at the school. Others continue to do the school runs and parents are mixed on if it is ok or not but certainly something to bring up at interviews.