ski luggage on shinkansen

My girlfriend and I are planning on catching the shinkansen from Tokyo to Nagano and back over the New Years period.

I understand that this is a very busy time of year for travel, and that the shinkansen have limited luggage storage space.

Does anyone have any experience in transporting ski equipment on the shinkansen?

Our board bag is approx 190cm long and quite hefty.

There is limited luggage space on the Shinkansen - I haven't seen people taking skis...most Japanese people take advantage of the luggage shipping service (takkyubin) to send their ski gear ahead of time. If you are in japan before you head to the slopes, consider doing this - the cost is reasonable, it's very reliable, and it leaves you free to travel on the train without worrying about your stuff. Your hotel can help you arrange this.
Oh, another consideration is that the Shinkansen stops are VERY brief at the stations and if you do take your ski gear, be ready to jump off the train quickly.