It takes 6 hours to reach Kanatal from Corbett. Yes there are buses and cabs to Kanatal from Corbett. Kindly check the weather for its monsoon time in Uttarakhand.
Yes it is Feasible to visit kanatal in January and Yes it will take 5-6 hours average to visit. But in January there may be snowfal so bus service may terminate . So check this before leaving. Things to do in Kanatal:
1) Camping 2) Trekking
3) Rappelling 4) Jungle Safari 5) Enjoy in Snow
6) Nature Stay
7) Sightseeing