OK, a completely serious answer.
The single thing that seems to have improved my skiing the most is just balancing. Initially, it was a summer just periodically catching myself in midstride while walking down the hall and balance there for 15 seconds. The people in the office laughed (and asked to see my day pass) but they know I am skicrazy so understood when I told them what was up. Subsequently, I have expanded that to trying to balance on one foot while taking off shoes or putting on socks, etc. Activities that require more movement and therefore more subtle movements. This is probably especially worthwhile for me because I've had a couple of back problems and loss of muscle mass, and recovery from that difficult. Hard to find exercises to replicate the running and jumping that was easy as a kid.
However, my guess is that given your skating activities you wouldn't gain from this the way that I did.
Road bike has been good for me as well for similar reasons. Good way to restore strength while exercising combinations of lots of muscles in a more dynamic setting with variety of speeds and varying resistance just naturally ocurring. And, of course, has the cardiovascular advantage as well. For me, road bike works better than trail bike. There are plenty of paved trails in the DC area and the road bike gives me a greater range to ride. The WO&D railroad trail is about 45 miles paved total. National airport to Mount Vernon is 12 miles paved and scenic. Lots of other lesser 10 miles trails here and there, not to mention just riding on the road.