Of course. The only concern might be trying to make a reservation too early -- i.e., if one half of your points is from a January Use Year while the other is, say, for an October Use Year, you might have to wait until "whenever" to have access to the points from the October Use Year. I can't imagine having to wait more than a few months before being able to use all of them, though you might have to "bank" from one or "borrow" from the other to get them to a point where it will work in the system.
