Well, I got cold feet and decided to go with what I know. So it's a schelp down to Dublin on the bus, staying overnight at a friend's, then to Dublin airport for the 11+ hour flight with the two kids. At least this way, we clear immigration in Dublin, and don't have to transfer baggage half-way there, and the travel time, even if it's cooped up, is shorter. So the hassle of the transfer outweighed the hassle of getting to Dublin and back.
How I'm gonna handle a baby and 5 year old on the plane is going to be another matter.
On the plus side, yay! We're going home for a visit this year! Yay!
Tips for traveling with baby + kid will help, although as it's closer to travel time I'll probably start a new thread.
Thanks you guys for the input, it helped me sort out which way to fly.