I'd sit tight and use it, maybe with the side panels off, and see if it heats up enough to throw the idiot light and whether it belches coolant out of the overflow. You're not that far over the temps Skwirl reported with his tractor. You can bet the dealer will be pricey, and will probably recommend a new head if it's leaking under pressure. If it keeps overheating enough for concern, that's probably the culprit...you could pull the head, clean it and inspect it...there may be a shop around that can check it off the engine. I'd just use it and be watchful, summer's over up your way, and get your fall chores done with it. Can't remember if you move snow with it...don't have to deal with that as far south as I am. You could probably buy a backup machine for about what it costs to core/rod the radiator, up your way, and definitely for the price of a replacement radiator. Don't toss the towel yet...walk away from it for a while, time will help you figure out your next step.