It's just easier to make a hole exactly where it will work best for you and you can get one of these Winegard cable entry plates that are used to bring antenna cables from a dish to inside the rig. You use the self leveling Dicor under and around the plate and screws and you will not have to worry about a leak. We had our Trav'ler dish installed over 6 years ago and a three cable entry plate was used and have never had a leak.
https://www.amazon.com/Winegard-CE10...le+entry+plate