Capsule hotels fully booked in golden week?

Am I correct in assuming some capsule hotels are unable to be booked in advance, giving me as much chance as anyone else of getting one in Sapporo for a couple of nights? Is there any chance of me securing anything cheap-ish there for a couple of nights?

Golden Week is primarily a time for travel and tourism, often in groups or as family. Business activities tend to be low. Capsule hotels tend to be popular among business people, not tourists. Consequently, I would be surprised if any capsule hotel in Sapporo would be fully booked out over Golden Week.

In general, people worry too much about hotels booking out. If you are a little flexible, you are fine anywhere, any time, except maybe in central Kyoto. There are plenty of available rooms (capsule or otherwise) at reasonable prices in Sapporo during Golden Week.

Actually, Capsule Hotels are often used by young travelers and travelers on a budget (in addition to business travelers), so they can and do book out during peak travel times and weekends. I think most can be booked in advance.

Capsule Inn Sapporo sill has available rooms during Golden Week and can be booked online:
http://www.capsuleinn-s.com/reserve.html