I was Nordic varsity back in college. I had a road bike then, but didn't ride in winter. We ran on foot a lot as well as on skis, especially in knee deep snow. It's vastly more technically demanding than cycling and uses a lot of upper body and core. That's how XC skiers get those incredible VO2max numbers.
Did you get skate or diagonal gear? I never skated but folks tell me that it's better for cycling. Skate didn't exist back when I ran XC a lot.
XC certainly helped my fitness. In the spring, I had no problem getting my bike up the road.
I mostly ski Alpine now. That was always my first love though I was a much better Nordic skier than I ever was Alpine.
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