We will be driving from Dublin to Dingle in 1 day. We would like to stop in Kilkenny and Rock of Cashel for sure and possibly Powerscourt and Glendalough. Is this too ambitious? If so, what should we eliminate?
IMHO Kilkenny
All of that, in my opinion, is far too much for one day. If you get a good start, I think you could possibly stop in Kilkenny and the Rock of Cashel. But you wouldn't have a ton of time at either.
If you left at 8:00 a.m., you could be to Kilkenny by maybe 9:45. Spend two hours or so there (which is not a lot of time and wouldn't do the town justice), then drive an hour to Cashel. Get lunch and see the Rock. Maybe you'd be on the road by 3:00 or so. Cashel to Dingle is another 4 hours or so with no stops if I recall correctly (it says 3 on Google Maps, but it always takes a lot longer when you aren't on the highways in Ireland).
But I would absolutely not even try to go to Powerscourt or Glendalough in the same day that you drive to Dingle. For reference, we went to those to places on our way to Kilkenny (where we stayed for the night), and arrived at our hotel in Kilkenny around 5:30 or 6:00 p.m. And we left Dublin around 9:00 a.m.
Agree with Steve....too much for the first day!
If you want to do Powerscourt and Glendalough then plan on spending the night n Kilkenny. Get up the next day and drive to Cashel on your way to the next stop.