It is almost certain that this flutter will come back. They almost always do. Because the ablation is a low risk procedure I would suggesting pursuing it at this point. More importantly, you should continue to follow with you cardiologist even after the ablation because those patients who have atrial flutter also may have atrial fibrillation.
My brother had atrial fib also also brought on by exertion. His did not respond to medication though and ended up having an ablation. He is now fib-free.
I am surprised that your insurance would approve an ablation before you had explored the medical route.