You may want to try Digi-Key (1-800-344-4439).  That temperature range will
be pushing the specs.  So, you probably will need to go to some of the
crystal manufactures, such as CTS, Epson of AMerica or ECS.  Sounds
like a military temperature range??
By the way the official operating specs for the pic chip is 0 to 70 C.

Mike