As long as you aren't past the PIF date, you can cancel now and receive full refund. I believe the only exception would be if you are cruising concierge, in which case the deposit is non-refundable but you can push it out as often as you wish.
If you have past the PIF date (generally 75 days prior to sailing but some cruises are further out than that), you'll be in the penalty phase. Depending how close you are to sailing would determine how much you lose.
Enjoy your cruises when you finally get to go!