There is no fixed size one can say that a binary for a GTK+ application will be. There are far too many variables that determine what size it will be.
There are many examples here listed or linked on the tutorial section of this forum - http://www.gtkforums.com/viewtopic.php?f=3&t=988
Since I do not use Windows for application programming I can not help you running your application and from previous postings I think that it is advisable not to compile with static libraries.
Did you look at the download page - http://www.gtk.org/download/index.php
and follow the correct links for the system that you want?