Waterfowl Lakes is the largest campground on the Icefields Parkway - it has a total of 110 sites and all are available on a first come, first serve system (no reservations).
This campground is an ideal place to be based for a longer Icefields Parkway adventure. Hiking trails are accessible right from the campground and the midpoint location makes it easy to access plenty more in either direction.
The Waterfowl Lakes themselves are beautiful and there are some really lovely walk-in tent sites as well. If you do decide to stay for a while, note that there is no cell phone signal here.
A Parks Canada parks pass is required to explore Banff National Park ($22/day for a vehicle of up to 7 people).