Edmonton became our prefered point of entry because the airport and TSA/Customs were very traveler (hunter) friendly along with hotels.
We flew United each time without a hitch, booking flights "about" 90 days before our planned departure dates. Additionally, we made the trips with one stop each time. San Antonio - Houston - Edmonton and Nashville - Denver - Edmonton.
As for pricing - we found that booking the flights on a Tuesday or Wednesday seemed to mske a difference by a few bucks. Also, if youre using miles consider flying "out" of your home area on a Friday rather than the weekend. It saved us a bunch of miles.
Hope this helped.
One thing we did was give up the Cabelas Visa and went to an American Express Delta Skymiles card to rack up as many miles/points as possible. It really helps a lot as we generally fly each year to Los Angeles (our son lives there), to Winnipeg and in the winter to Fort Myers. We pay very little for these tickets by using our points from that AMEX card.
If you’re not going til 2020, you’ve got lots of time to do the same. We put everything we can on that card and never keep a balance or pay any interest.