Keeping cablebox on constantly for Tivo?

Previously I had basic cable (no box) from cablevision, and plugged the cable right into my Tivo DVR and everything worked fine, I could watch one show and record another, I could power everything down and Tivo would turn itself on to record, etc. I just ‘upgraded’ to iO which needs a cable box, and now the Tivo has to pull the signal from the box, which means it has to be on the same channel and has to be on. My question is: Do I now have to leave the cablebox on constantly in order for Tivo to record during the day? What happens if there’s a power failure (typical in my area), and the cablebox turns off?

Addendum: My TV has a slot for a Cablecard, would it be better to use that, lose some of the functionality of iO (like Pay-per-view, which I’ll never use) but have the signal avoid a cablebox?