Check out Hoshinoya Karuizawa, a luxury resort just outside the town of Karuizawa, which is one stop, twenty minutes, shy of Nagano on the Nagano shinkansen. Mr. Megatop and I stayed there for two days in December 2010 and liked it quite a bit. It's an interesting combination of rustic and modern and definitely accessible for foreign visitors who might not be comfortable going whole-hog Japanese-- it's not a traditional ryokan with just tatami mats and such. The rooms are quite large, parts of villas organized around a soothing mountain stream. There's a private spa and onsen facility within the hotel, and there's also a public one on the hotel grounds. Mr. Megatop and I used the public one and were perfectly comfortable and welcome there. As for ski areas, there's a popular but (I'd guess) not terribly challenging area of runs just on the other side of the shinkansen line. I assume there are several others nearby. And for serious, Olympic-level skiing, Nagano is not far away.