Joe,
Our closest event in California seems to be a show at Mather Air Base in March. I too have been looking for warm and/or aviation event destinations but they don't plan much fly-in-wise that I've found in the cold, and nothing is coming up besides Florida.....
We have been nurturing a NorCal Canard group that has had some success this fall:
http://groups.yahoo.com/group/norcal_ezWe have had several fly outs of two or more and are hoping to improve that this spring. We made Shelter Cove one day for a great lunch. That is one of our most spectacular airports where you can fly in and eat/stay/golf on the coast. I've forgotten your home base but from Idaho Falls its a 3.5 hour flight and would be a great weekend for you and your lovely GIB.
We have been pretty quiet over the holidays but should be picking up soon. We'd also be very interested in semi-day trip/maybe weekend jaunts up your way if you can "show us the way!"