I don't know of anywhere inside Epcot where you could watch, but the ESPN club is a great place to catch a game! If you go over about 30-45 minutes before the game starts (if it's an early one), you should have your choice of seats. Grab a table, order some appetizers and settle in. Last time we had a booth with our very own little tv right at the table, but if you tell them what game you're interested in, they'll be sure and seat you at a table where you can see it. They show every single game on multiple sets, so you should have no problem. During the breaks and at halftime they do some live interview stuff and trivia contests -- it's pretty fun.
Go Chiefs!!