I'm trying to temporarily set up my campy 10 speed road bike for a serious hillclimb. Everyone has suggested that a 10-speed mountain rear derailleur with 11-36T cassette is the way to go (in order to get to a 34x36 ratio). All other solutions involve more significant drivetrain changes.

My question... are the SRAM or Shimano MTB 10-speed derailleurs compatible with campy ergo road levers?

The other options are less appealing (triple campy crankset with new 12-30T cassette only gets me to 30x30, and otherwise would need to replace just about everything using some combination of SRAM or Shimano mountain components).

Any ideas? This is to get up Mt. Washington in New Hampshire.