Originally Posted by
bbmatt
how are you searching, when i put in my dates, I get: "We're sorry.
We were unable to find anything available that met the conditions of your last request.
Please adjust your search conditions and try your search again"
even when I use the Japanese version, I get "誠に申し訳ございませんが、この検索条件に該当する空室が見つかりませんでした"
Which means no vacancy according to google translate

I searched Rakuten Travel for Niseko region - 1 room for two people
http://travel.rakuten.co.jp/yado/hokkaido/niseko.html
On 26/Dec, the site lists rooms at
Natural Resort Niseko Weiss Hotel
One Niseko Resort Towers
Niseko Onsen Niseko Grand Hotel
Hilton Niseko Village
etc.
On 27/Dec, the site lists rooms at
Niseko Park Hotel
On 28-30/Dec, the site lists rooms at
Niseko Tokyu Resort
TBH, those last two places don't look all that good to me and the thought of moving from one accommodation to the next does not appeal. I'd probably opt to visit a different resort. But If Niseko is whatcha want, then those appear to be available.