A friend of mine was in the exact predicament almost two years ago. While he only had the interview at UAL, he chose to go to training at Alaska and not continue the UAL process. His initial thoughts were the same as yours and his time left was 27 years at the time. I believe he is happy with the choice he made. He still does a bit of “what if?” when he sees a 777 or 787 taxi by but driving to work (plus one ferry for him) is hard to beat and if you go to Alaska with realistic expectations you will be very happy. My .02