First: In your Footer property set height to 0in.
Second- don't use the build-in Footer. Instead, use a sub-report that will contain your footer details.
Now, you need to define the sub-report as thin as possible in the main report (while in the actual sub-report - arrange your data as you want).
now add a page footer(in your sub report) you should right-click on the design surface, point to Insert, and then click Footer (Or it can be enabled through the Report menu –> Add page footer in BIDS ).
You could put the rectangle into a page footer and set its Hidden property to:
Strech the rectangle to cover all the footer area, then your are good - the footer will not be displayed until the last page.
I think it will resolve your purpose.