I would suggest choosing Option B because it appears to provide a more even schedule with less time spent driving, which should be better when traveling with children. When you visit Grand Teton, think about staying at Colter Bay Campground; it is good for families and the views are very beautiful. When you travel from West Glacier to North Yellowstone, it might be good to stay in Missoula on the way. This town is pleasant and has places that are suitable for families. While returning to Calgary, consider visiting Waterton Lakes National Park; it is very beautiful and has excellent hiking trails that are appropriate for children. Have a pleasant journey!