Hi Nicole,
Instead of thinking in terms of paying for the entire vacation, consider making a room only reservation.
By booking your room at your chosen resort, you'll insure that you get your first choice resort. A deposit of one night's room cost plus tax will hold your reservation. Then, if you want to convert to a package, you can modify your reservation when you have funds available.
If that's not an option, I would also suggest placing a "courtesy hold" on a room only or package reservation at your earliest convenience. Instead of making a deposit, you select the option for a courtesy hold. This is generally for 7 days before payment terms and conditions apply.
Whether your resort will be available depends on its popularity. One suggestion is to
price out your vacation and see if any standard rooms are available. A good sign that a resort is filling up is when standard rooms are no longer available.
A certified Disney Travel Planner may be able to offer more assistance. I recommend Small World Vacations and Dreams Unlimited for your Disney vacation planning needs.
Enjoy a wonderful February vacation to WDW!