If you plan on hunting anywhere that's listed or known as a "Migration Area", then sit on your thumbs until you get definitive confirmation that big snows are imminent. Then haul-ass for your hunting spot. If you're unable to be that flexible with your time off, then research for an area that has a resident population.
Migrating elk are not much different than migrating waterfowl. When the migration is on in the area you're hunting, there will be opportunity. If the elk are either not migrating, or have already mostly moved through the hunting will be very difficult. It's all about timing and numbers.
