There was a 46" Crash Tender on the water at the Oxford Model Boat Club a couple of days ago, performed very well on a pair of 2836 1000kv out runners, on 3S Lipo packs. Certainly didn't lack power, and by using a mix in the transmitter the owner was able to manoeuvre the model very accurately.
I was surprised at how well it went on such small motors, but the proof was on the water. No shortage of running time, either.