I will be serving a baked potato bar for my son's graduation (150-200 people). I planned on cutting in half, applying olive oil and then cooking for about 30 min. At that point I need to keep the potatoes warm. I was thinking either a preheated insulated cooler or roaster. Which do you think will work best? They will need to stay warm for approx. 5 hours. Thanks so much for your help!

You are on the right track to use a pre heated cooler or roaster, but five hours is way too long to expect them to stay warm. They usually are good for one to two hours using those methods. Cutting the potatoes in half to cook might not be your best option (see links below). Potatoes are fully cooked when the internal temperature reaches 210 degrees F inside, and partially done at 185 degrees F.

Here are some helpful links:

• Baked Potato Bar for 150 People
• Baking Potatoes for a Large Group
• Pre-cooking Baked Idaho® Potatoes