Activities and places to visit outside Niseko

We're staying at Niseko Village for 3 nights and intend to do day trip visiting nearby areas before returning to Niseko Village for dinner. Can you please recommend nearby places of interest?

Will you be driving? If not the closest place that you can visit as a day trip is probably otaru.
http://www.japan-guide.com/e/e6700.html

If you will be driving, you could also visit lake toya
http://www.japan-guide.com/e/e6725.html

Thanks. After Niseko, we'll be staying 5 nights in Sapporo thus is it nearer to go Otaru for day trip from Niseko or Sapporo? What can we do in Hirafu and Kutchan?

During our stay in Sapporo, we plan to visit Furano and Tomita Farm. How do we go there from Sapporo?

Are you going there during winter? Then Niseko and surrounding is basically a ski resort with ski sport activities. Beside that, there is really not much to do. If you have no interest in ski, I would suggest you go somewhere else.

Otaru will be slightly closer from sapporo which is about 30-45mins compare to 100+mins from niseko.

As for furano, the direction is explained here
http://www.japan-guide.com/e/e6826.html
Again, if you are going there during winter, there isn't really much worth seeing as most of the flower will be covered by snow.