I have JB travel credits expiring this year totaling about $1,700. Had this idea.

Before those credits expire, use them to book a flight at least equal in value to the amount of the travel credit (for sometime in the future). If it turns out we cannot take that future flight, MODIFY that itinerary and select another set of flights in the future we think we can make (with a cost at least equal in amount to the value of those flights). I am thinking as long as we don't CANCEL the flight purchased with the travel credit, there won't be any amounts that post back to our travel bank to be forfeited. If this works, it would seem we can continue doing this until we end up taking flights which use up the travel credit.

Does anyone know if this strategy would work? If not, why not?

Thanks,