Thank you manderwa for the info !

I will for sure have a 4-wheel drive rental car with snow tires, and have years experience driving on snow since I used to live near Buffalo, upstate New York, right in the middle of snowbelt region, so driving on the snow isn't a problem for me. The only concern I have is whether the highway will be completely closed during heavy snow or if snow removal on highway is done efficiently and frequently.

If I go for the seashore 北陸自動車道 and 東海北陸自動車道 (Hokuriku Expressway and Tokai Hokuriku Expressway), will I be able to see some beaches, cliffs and the ocean like the California Pacific Coast Highway scenic route 1 ? I hope I'm not expecting too much lol