I got a G2G 2 year and in the fine print it says that you have to be full time status and need to graduate in the appropriate number of semesters.
You're going to have to do a 104R where you list the classes you need to graduate by semester and all the other pertinent information - including credits required and number completed. I'm willing to bet trying to use all 4 years would put you under full-time status. You've got to submit transcripts anyway and it's tough getting one of these scholarships... I'd suggest going for a 3 year instead.