Questions about Hokkaido 10th Feb vs 18th Feb

I would love to go to Hokkaido during winter for a 10 day trip for solo travel. It will be my second trip to Japan.

I am trying to decide between, starting my trip around 10th Feb or 18th Feb.

I know the hostels/hotel prices are higher during the Snow Festival. It would be nice to see, but I don't mind skipping it. My main concern is the crowds and getting around with my luggage (Size is just below the Shinkansen oversized measurements). I would like to stay in Sapporo, Otaru and Asahikawa.

1. How are the crowds after the snow festival? Do majority of people stick around to explore Hokkaido?

2. Is the Snow Festival busier in the beginning or end?

3. Onsen towns easy to access with public transport?

4. Any recommendations on things that need a booking?

Will appreciate any response