The shuttle service from Karuizawa Station is very convenient, you just need to make a call day before for seat reservation. Though, me and the receptionist had a hard time understanding each other over the phone (since I don't know how to speak japanese) haha the reservation was made. I think you just need to say your name, "shuttle reservation", time and "tomorrow" hahahaha. The hotel is kinda old, but I do not mind since the views from you room and the outdoor onsen are breath taking. You can also request what view from your room you'll be wanting to have. This Hotel is also very near to Prince Hotel where the Ski Resort is. I wasn't able to eat at their restaurant since it is kinda expensive (for me haha) but there is a store where you can buy snacks like cup noodles, bread etc. Also, in your room there is a towel and robe that you could use for the onsen. The outdoor onsen is common and you can use this towel to cover your privates.