My wife and I discuss moving the family to Kelowna every time we go out there (which is 2-3 times per year). I have family living out there as well which provides a bit of incentive however it always comes down to the work thing for me. You spend so much of your life working, money is a part of it sure, but I'd make damned sure you are going to enjoy the work you do out there. I know for myself I work in O&G as well and I enjoy the challenges it brings, I am not sure a cushy government job would keep me engaged to the point where I am satisfied.
Not saying we won't move out there some day, if everything else is equal it seems like a great place. But I'd definitely make sure the job is a good fit first. As others have said though, as long as the experience is relevant and you have a high-demand skill set than the worst case scenario is that you'd have to move back if it didn't work... Not so bad.
An additional plus is that it's a good time to sell here and a good time to buy in Kelowna, so it's possible a few years out there could improve that side of your financial situation. It's not like that valley will ever go down in demand, there simply aren't a lot of places like it in Canada to live. Oh, and if you DO need a realtor out there, I also know a gem of a "guy" (my wife's uncle
).