Yes, you can cancel the one trip and use same points for another as long as (a) the date and place you want is not booked full, and (b) the trip will be during the same use year as that February trip. If you are looking at doing it in a later use year then those borrowed points will not be usable (because you cannot send them back to their original use year) and any current year points in the ressie would have to be banked and whether you can bank depends on when your last banking date is.