The first time we went to DL, we didn't bring our stroller since our LO hardly uses it at home. Bad mistake! So I rented one from DL, bad mistake since we couldn't take it out of the park area, so lugging a 3.5 yo the distance to the DL hotel after a long day of walking 7 miles already in the parks was torture. We've made it a point to bring our Uppababy G-luxe stroller each time (a step above an umbrella stroller but still portable and foldable). We just went earlier this year and LO is 5 and we really used it. She lay in it when we were walking back to the hotel late at night, what a huge help! Also, when she was walking, we put our stuff in it, again, a huge help.
If you are staying at GCH, you can debate needing a stroller or not since it's so close, but if you do rent, rent from citystrollers, as they will deliver it to your hotel.