My novel lengths and status at the moment:
Gerald: Upper MG, Humorous Fantasy - Querying - 77,000 (HP published at 77,500, Terry Pratchett Upper MG novels consistently 90k+; novels from these two authors I used for reference. JKR's was a debut but obviously TP is very well established.)
Jaguar: Upper MG, Contemp Fantasy - In Revision - 70,000
Wilfrid: Upper MG, Medieval Fantasy - WIP - heading for high 60's
I have seen a wide range of word counts for Upper MG but I think fantasy gives more leeway. I do think that Gerald's word count may be hurting my query although no rejection has mentioned it yet.