hokkaido summer trip arrangement

We family of 4 would like to visit Hokkaido covering the following places from 16 to 23 June 2019 by self-driving:
-Sapporo
-Otaru
-Lake toya
-noboritbetsu
-Biei/Furano (and Asahikawa)
We will arrive on 16 june and leaving on 23 june. Would appreciate if anyone can advise on the route/sequence of my itineraries listed above in term of the flow of expressway, time and conveniency. Should we rent the car starting from new chitose airport or from Sapporo?
Regarding accommodation, we prefer to stay together in one room (kids ages 13 and 15). Wonder if the hotel in Hokkaido is by head count or by size of room? We read the news about the rules set for Abnb. It is ok now for us to book with Abnb or Hotel better? Thank you.

Hi. The Sapporo hotel that I booked charged per room but a maximum numberof guests was indicated in the website (like 1 room for 3pax). We also booked a ryokan but the charge was per head. Didn't look into airbnbs though.

Thank u for yr infor Andrea.As sapporo hotel is charge per room,do we need to provide exact number of people stay in the room when booking and whether we need to provide passport of all during check in?do we need to inform them if there is any change of number of stay/name?