I've been in water up to the bottom of my rock rails. No water issues, but would not expect it since the level was still below the door sills. More than water into the cabin, the main concern for me would be water getting into the oxygen intake. That's where the major head aches would occur.
2015 Cherokee Trailhawk:
Granite Crystal, 3.2L V6, 8.4 Nav, black leather, sunroof, tow, tech, comfort/conv, no hood decal, 9 speakers, CD player, Maximum Care lifetime warranty, Mopar first aid kit, rear rubber cargo mat, Thule Aeroblade cross bars (black), Thule Rapid Aero feet, Kuat Vagabond X cargo basket, RRO rock rails with smooth covers, Mopar door sills, Raingler ceiling net, Raingler seat headrest handles, MFC aluminum lift kit, RRO winch bar and Warn M8000S winch, BFG T/A KO2s