There will be a lot of road construction on Route 2 near the park, so you will need to have a pass specifically to be allowed to drive on Going-To-The-Sun Road (separate from your usual entry pass, and you may not get one). Air fare into Glacier International is really high this summer, and it's also difficult for folks to secure a rental car. While hotels aren't completely booked solid, it's a lot more sparse than it would normally be.

The low availability and high prices may also be true for the area around Banff (+3 parks in Yoho, Kootenai, and Jasper, but you almost might as well treat it like one gigantic park), but there may not be a ton of construction on Highway 1.