Hokkaido in late jan

hi,
is it okay to go to hokkaido in late jan ? I am thinking of going to see the drift ice and take the tourist ice train, but is it worth going all the way from tokyo to see that?

Will the national parks be accessible by public transport and is it okay to drive or conditions will be bad ?

Any other recommendations or things to see in hokkaido, apart from otaru and sapporo ?

but is it worth going all the way from tokyo to see that?

It depends on your time and budget available and on your personal priorities.

But note that the drift ice has become thinner and thinner in recent years, and on some days may be barely visible, at all. But if it is there, it is a nice experience.

Will the national parks be accessible by public transport and is it okay to drive or conditions will be bad ?

Public transportation is bad in Hokkaido's national parks, especially in eastern Hokkaido and especially in winter. But there is some. If you have the confidence of possibly having to drive on snow covered roads, I recommend to rent a car.

Any other recommendations or things to see in hokkaido, apart from otaru and sapporo ?

More ideas:
http://www.japan-guide.com/list/e1101.html