We have just started going every other year. I bank then the next year use the banked and current year points. I book enough to have to borrow a few points. Then, the following year I can bank the remaining points again. It gives me more flexibility to change up my vacation plans. So, if I decide I want to go 2 years in a row, I always have my current years points to use if I want.
The risk depends on your vacation dates and use year. If your vacation is right after your use year, you have nearly a year to use the banked points before they expire if you have to cancel. If your vacation is closer to the end of your use year, you have less time.
Of course, there is risk the other way as well. If you are used to borrowing most of your points, the current 50% borrowing restriction could mess with your plans as well.