Ok, I'll just go a different route.
Had a Koyo encoder fail on me because I didn't heed the temp specs

. It needs to be good for -20 F. Found some that are good for -40 F but they either have Profibus, Canopen,SSI or the like.
Seems the only type of encoders that have extended temp range are of the Magnetic type.
Wonder what prevents the optical types from going that Low.
Thanks for your reply.