If you exchange through II, you will only be able to trade for a "comparable exchange". According to II, that means that your 1BR usually won't pull a 2BR, except (1) at resorts that have only 2BR (or larger) units or (2) within the last 60 days before your hoped-for check-in date (as potchak indicated).
Thus, since the two Aruba Marriotts have 2BR, 1 BR and studio units, it's unlikely that you'll get a 2BR for your 1BR, unless you snag one during that last 60 days.
There is no way to get a 1BR and upgrade it to a 2BR through II or Marriott.
An alternative, if you are able to trade for a 1BR, is to rent a studio - through Marriott or more cheaply on the open market - and ask Marriott to put them together as a single 2BR unit, as discussed
here.
The other alternatives are to try for a direct exchange with another owner through
www.ownertrades.com or to use one of the small independent exchange companies.