As noted, even if you have a lockoff reserved, you can't just downsize without canceling and rebooking which would cause you to lose your reservation if there were a Wait list for even one day. But you can use some tricks if you have the points and willingness to do so. You can reserve both a 2 BR and a 1 BR and then cancel the one later you don't need. Even if you can only reserve part of the time for the second unit size you'd still be way ahead. And if you were looking at spending points on the weekends, those days are almost always easier to reserve so reserving both unit sizes for the weekdays and holding out for the weekends is a fairly safe bet. Worst case scenario is you pay cash for the weekend or end up trying another resort. Another option is to reserve a 1 BR and studio separately. It's a few more points and no way to guarantee they'd be together as a 2 BR but likely the safest single option if you don't have enough points to do both units and the extra points is not dramatic. And there's nothing stopping you from making the attempt (or wait listing) to change back to a 2 BR later if you find out you definitely need it and still potentially saving those few extra points.
