Leftover Storage & Reheating: Let any leftover French Bread Sloppy Joes cool to room temperature, then wrap them in foil or store in an airtight container in the fridge, where they'll be good for 3-4 days. When you're ready to reheat, pop them in a preheated 350°F oven for about 10-15 minutes, or if you're in a hurry, give them a quick zap in the microwave for 30-60 seconds.