6 days holdiay in Hokkaido, suggestions?

This will be our first visit to Hokkaido. We have 6 days to plan for with initial arrival in Sapporo. Cannont decide to go October 2nd or Nov 23. Any suggestion? I am easy to satisfy as I am only there for fresh seafood, my husband is more into handicrafts and history.

I would go in Oct. because early Oct. is a good time for autumn foliage in Hokkaido. Sounkyo Gorge and the Houkeikyou area are 2 popular destinations for seeing beautiful maple colour:
http://www.sounkyo.net/english/index.html
http://www.houheikyou.jp/english/index.html

Another autumn special site is the Lake Notoro on the east coast. The lake glassworts turn red during Sept./Oct. and make the area looks like a giant red carpet. The only thing is that it would involve long distance travel from Sapporo all the way east to Abashiri which is just south of Lake Notoro:
http://www.flickr.com/photos/53884065@N00/366993377/