Perfect for tailgating! Prep the potatoes at home, wrap them in foil, then toss them on the grill when you get to the game.
In a large nonstick skillet, cook the bacon over medium heat, stirring often, until some of the fat renders, 1 to 2 minutes. Add the rosemary and maple syrup and cook, stirring often, until the bacon is browned and crisp, 6 to 8 minutes; season. Using a slotted spoon, transfer to a paper towel–lined plate; reserve the drippings.
In batches, microwave the potatoes until tender, 5 to 7 minutes per batch; let cool slightly. Slice the potatoes Hasselback-style (cutting thin slices crosswise almost all the way through).
Stuff the cooked bacon and cheeses between the slices. Wrap individually in foil sprayed with cooking spray; transfer to a cooler. Once you get to the location, heat the coals in your grill. When the coals are covered with ash, push them to one side of the grill. Place the wrapped potatoes on the cooler side of the grill. Cook, shifting around often for even cooking, until the cheeses melt, about 5 minutes.