I wouldn't say the Castle Mountain Chalets will be closer to Banff than Canmore (and Baker Creek almost certainly not), but they're beautifully situated along the Bow Valley Parkway, and Castle Mountain Chalets are at the junction of the very short connector road to the main highway (Trans-Canada, or #1) which will get you places faster. Baker Creek is a few minutes from the road leading into Lake Louise. However, Baker Creek Chalets is on our bucket list - we've stopped there for a stroll and picnic lunch along the river. Glorious!
Canmore should have quite a few options for you, although availability will still be a factor. Many of the condo complexes have vacation rentals, so those are likely your best bet for a comfortable place for 4. Check reviews on Tripadvisor and the like to get an idea, but some places include The Lodges at Canmore, Falconcrest Lodge, ummm... Sunset Resorts, perhaps? These are all located very close to the #1 highway (so there will be some amount of traffic noise, and the occasional train comes through nearby as well) but that also makes it quick to get to Banff and beyond. Also don't neglect the Kananaskis region east of Canmore - the drive south on highway #40 has some stunning moments and is usually not as busy or crowded, but there's also fewer options for organized activities. If you're good to do some trails or make your own fun, it's wonderful.
Canmore itself is quite nice, too. Not as iconic as Banff, but a little quieter and many many fine restaurants and some good shopping.
You might even try airbnb and some of those kinds of places for condo owners who are renting out their places.
Hope that helps!
Bart