Buying seafood for skiing trip to Niseko

We are 3 families of 10 pax planning a skiing trip in Niseko between Dec 22 to Dec 28. We are travelling from Hakodate and will be staying at a large self-contained holiday house equipped with full kitchen so we are thinking about buying seafood and other fresh produce to do own cooking during our stay. My questions are:

1) is it possible/advisable to buy fresh seafood (squid, crabs, salmons etc) from hakodate morning market and bring it to Niseko (we are self-driving on rental vehicles)

2) is it better to buy beef (waygu) in Hakodate (and where are the recommended stores?) or in Niseko or Kutchan (and where's the recommended stores?)?

Thank you very much for helping - really appreciate it :)