Hi Vasja,
The plan starts with 7 hours per week and peaks not that much higher, with 8 hours per week. This is because this plan focuses on gym workouts and musuclar endurance.
As for cycling. This article is targeting to ski mountaineering racers, but it holds true for all skiers, cycling isn’t an ideal modality.
If you really want to use cycling as a training modality within this plan you’ll need to double all the durations. So a 1 hour Aerobic Capacity workout done on foot has to become 2 hours on the bike. The bike is just too efficient, and the movement (pedaling in a small circle) too different from what the legs must do while skiing.
Hope that helps. Best of luck.