Winter conditions in Hokkaido / Tohoku / the mountainous spine of Honshu etc. are very challenging. Very heavy snow fall. Very low temps. I certainly wouldn't get much of a kick out of it. You should also be aware that the ski resort areas get very clogged up with traffic at weekends in the ski season. On a few occasions I've spent hours (literally) in bumper-to-bumper traffic on a Yamanashi hillside. ("Snow joke" as they say).

You could head for points South - Izu peninsula, Mie peninsula, southern Kyushu etc. They're not as far "off" the beaten track (and in many cases they're very well served by public transport). But the scenery can be quite pretty.