Two years ago, I installed a SureCell system on our 34' Alante 31R. For proper operation, you
must put distance between the external and internal antennas.
I considered running the cable down the refrigerator vent, but that would still require a bit of internal routing to get the cable to where I wanted to mount the amp. Instead, I created a new access hole further forward, descending onto a cabinet void to minimize the impact inside. Though adding a new roof penetration is not ideal, I used a cable entry plate and lots of Dicor to safely secure and seal the cable.
The amp and internal antenna are mounted on the cabinet near the entry door, antenna vertically oriented down. It's worked perfectly for two years, and no issues with leaks.