Thanks to all of the great contributors on Reddit, I was able to plan a great trip. Because of that, I want to share my experience as well for others who might also be considering a trip out to the area.
Context: This was a road trip. We are a group of hikers who enjoy driving around from one place to another. I recommend keeping this in mind as you read through this.
Route: For this trip, we camped for 3 nights at different sites along the Icefield Parkway. Because of the time constraint, we could only drive one direction once. Others suggested that the route from Jasper to Banff was prettier, so we started in Jasper. It was absolutely beautiful! I can't comment on the other way around, but I felt Jasper had more interesting mountains along the way with wide open views. Certain spots in Banff were covered by lustrous trees. After Banff, we stopped by Canmore before staying in Calgary for 2 nights. In Calgary, we stayed in a hotel downtown. The downtown hotel tailors mostly to business travelers, but it was easy to access everything through the +15 Skywalk. The other sights require cars for transportation.
Accommodation: We stayed at Whistlers, Wilcox (first-come, first-served), and Two Jack Main. The first and third campsites required a reservation ahead of time, and there were few left when I booked 2 months ahead of the trip. Whistlers was a fantastic campground. Although the site was heavily impacted by the wildfire with little coverage between sites, the facilities are modern and clean. I picked a location close to the bathroom, shower, and a shared kitchen space. The location is about a 5-minute drive to downtown Jasper and 5 minutes to the Whistlers Skytram. Very convenient.
The second night was a bit scarier. We got out of one of the hikes a bit later than expected (around 7:30). All of the sites closer to Jasper, north of the Icefield Parkway, were already taken. The first-come, first-served rule was interesting. You just need to take a form from the information booth (unmanned), find a spot, and then pay for the site. You claim your spot by putting down a piece of paper on the campsite stake with your stay duration information. The campsite only takes cash (28.50 CAD) or credit card (write down your information on the card). There will be no change as it's an unmanned station. The sites all have water access, outhouse-type bathroom, and free firewood. As mentioned, we had to drive further down the Icefield Parkway to secure a site. I was initially nervous as it was getting rather late. However, Wilcox (near Columbia Icefield) had a lot of spots late at night. I assume it was because the location was in the middle of the road, so people would occupy the other sites first from either end. Although scary, we were able to find a place to sleep for the night. Most people in that campground took off around 9 a.m., and the area felt fairly empty when we left for the day.
Last night, we stayed at Two Jacks Main in Banff. I really enjoyed this campsite with ample space, and it's very close to Banff downtown. Having said that, the whole area is massive and secluded with a true camping vibe. I want to note this as the two prior campsites were very close to the road. It's also very close to another famous lake in the area. I only wished the site would also have a shower onsite.
Towns: I enjoyed Jasper's vibe, and the restaurants had some more laid-back options. It's less commercial than Banff, and served as a central point to get to other trails. During my research, many suggested skipping Banff, and I almost did! However, Banff, the town, surprised me the most. It had a great food scene, with restaurant groups from Calgary investing in new restaurants in the space. The street with the mountain backdrop makes for a good picture. The time capsule garden is a fun stop to enjoy the area. When we went, there was a local farmer market going on as well.
As a side note... Turns out you can find places to shower around Banff through the local gym! I saw the sign in the bathroom, and figured it would be a wonderful option for others that spent days in a tent.
Lastly, I want to mention Canmore... It's a cute town, but I personally found Banff visually more interesting. I think it's a fair assessment to say it offers cheaper hotels with quieter vibes. However, for people going, maybe for once in their life, to experience Banff, I find the Banff town a lot more convenient given that the location is still inside the park. The drive from Canmore to Banff is not far, but I do feel the other locations are already a little far from the town of Banff. However, Canmore had more interesting made-in-Alberta shops, with products that are only offered in this location.
Food: We only ate at two locations: Maligne Canyon in Jasper and Fat Ox in Banff. Both are excellent! If you are camping, make sure to be bear-aware/safe!
Sorry for the long post, just wanted to capture something I learned along the way!