is Asahiyama Zoo and Biei in 1 day possible

Please bear with me with the slightly long paragraph of details I have on hand:

I've seen local tours by bus that takes you from Sapporo to the Zoo (3hrs) plus Blue Pond (30min) and Shirohige Waterfall (20min), then back. It's a 12-hour tour.
But it seems like no company does Biei tours.

I have 3 full free days in early February 2018 crashing with the Winter Festival in Hokkaido, of which I would like to spare 1 full day for a slightly remote place like Biei. (I have confirmed hotels everyday in Sapporo)

I read that people usually take JR from Sapporo to Asahikawa, change to a local train to Biei, then rent a 2-hour Taxi course that brings you to places you want.
The "Christmas tree" is the only reason for me to get there, the rest in Biei won't add up much for satisfaction. Since the cost-performance for this is quite low, I want to see if I could incorporate the Asahikawa Zoo into it.

The route would be Sapporo--Asahikawa--Zoo--Biei--Asahikawa--Sapporo.
Given that the sun sets around 5pm, I am not sure where I could leave Biei station right after sunset.