I would first recommend checking for a shuttle. I do know some hotels offer shuttle service to the games but, a lot do not b/c of cost for them to be allowed in the pickup staging area. (Jerry makes money any way he can...) If your are staying on the south side of the airport You will be about 7-9 miles from the stadium and a taxi will run about $30 each way. If your hotel is on the north side, expect to pay about $50 each way as you are about 18-20 miles away.
I have been to several events at Jerry's world, most recent being last weekend. I live 45 miles (north of downtown Dallas) from the stadium and it usually takes an hour to get home. I will give the city of Arlington credit, they get traffic moving pronto. Point is, don't be afraid to drive. The taxi lines are long and IMO unless you plan on drinking, not worth it... Parking is still available online for $35.00