I don't mean to be a Dream Crusher here but I just wanted to state that it's going to serve you far better to be realistic than optimistic with this process - always think of yourself as the rule and not the exception. I think you need to pull up your GMAT to be a serious competitor there.
If I were you I would applying to other schools for round 2, that are more in line with your GMAT score keep in mind that it needs to be higher than average to compensate for the grades), and apply to round 1 insead for January intake. You would have the round one advantage, time to retake the exam, and the opportunity to do an internship, which I think is actually good because the program is so intense 8 weeks of a break is actually quite needed in my opinion.
Having said all this, we really don't know enough about your profile to make a determination. If there's something about your profile that would add immense diversity to INSEAD, you could pull it off potentially.
If your quant score is a little bit on the low side I would recommend doing MBAmath.com and send the transcripts to INSEAD, along with others.
Of course, you will want to do a great job on the application as well. INSEAD has a lot of essays which indicates that this has a lot of influence on the decision. A good application can work magic in many situations, but wouldn't recommend that as your sole strategy.
Farrell Dyan Hehn, MBA
Admissions Consultant & Verbal Strategist MBAPrepCoach.com