While doing IMAX this morning I had an idea, but have yet to actually try it:
IMAX warm up step routine (right until she says "deep breath" and something like, "get ready for intervals". It's about 15 minutes).
MIC step section and cool down/stretch.
This would give you a great, intense step workout, about 45 minutes long. Good for those days when you want to work hard, but don't have lots of time.
Cheers,
Sandra