Thanks to those who responded to my question. For future reference, Ilford's response was:(posted 8297 days ago)"XP2 does not respond very well to push processing, although if you can find a lab that can do it, a push process will certainly not hurt. Unfortunatly, I don't think that there is anything that will give you better than marginable results. Good luck with it."
Lesson learned. At least now I'll never forget to check all camera settings if my camera gets inspected.
If anyone is interested in the results I do get from pushing the film one stop, let me know and I'll post the results.
J. Dawson