Unless you are referring to some sort of outside torque multiplier (like the low range on a 4wd transfer case) it doesn't get around the inherent design issues of torque transfer within a CVT.
Nissan in particular uses a "belt style" CVT. This is essentially a non toothed belt that is set between two variable diameter pulleys. It's clever, compact, and will transfer "some" torque. They have gotten around this low torque threshold in newer transmission by increasing the tension between the pulleys, and adding a traditional lockup torque converter to the front of the transmission. This allows the output to fully stop without the belt actually slipping. This reduces heat, but way of reduced friction. It's important to note that belt slippage only occurs during initial startup from a standing stop. That is the EXACT point at which most heat is generated, and most wear is placed on the belt. It is also the point when the torque differential between input and output is the highest. Also, when you'll be pulling a boat from a lake.
My suspicion is that the "low" your referring to simply keeps the pulley diameters in a higher numeric configuration, and helps reduce the torque differential between input and output as much as possible. It doesn't add any additional gear reduction behind the transmission, which would reduce the torque differential that is doing the damage. It most likely also maintains that favorable pulley config longer in the rev range, so as to aid in pulling. The inherent belt slippage without a torque converter will still be present, and overheating is a VERY real concern with prolonged usage (like dragging a pontoon up a ramp, out of the water, and then climbing up the next few hills to get back home.
Even on my traditional clutched planetary with torque converter automatic transmission, I can see 50+deg increases in fluid temp between boat launch and "the top of the hill" when climbing out of my local launch ramp. I have a large cooler with auxiliary fan, so temps never exceed acceptable levels. This transmission configuration also has no direct wear parts being affected during this use case, so fluid temp is the only real concern until clutch slippage occurs. The CVT doesn't have the benefits of that at any level. The belt WILL slip under extremely heavy torque loads. The questions really become "Can you keep the heat out of it?", and "How much torque transfer headroom do you have?".
This is a newer model that was tested under
SAE J2807, at least as best I can tell. If the OP can confirm that Nissan used that method to test the Pathfinders tow rating, then the CVT issue somewhat goes away. If the tow rating was determined by the marketing department, then that's an issue. My wife drives a Nissan Rogue daily. I can tell you I won't be putting any more load on that CVT than I have to, and it certainly won't be called into any amount of towing duty. Perhaps the Pathfinder has a more robust CVT in it, and it's not an issue, HOWEVER, if you're buying something new, then I would discount the CVT myself and find another vehicle you liked that has a traditional clutched planetary gearset. Bonus points if you find anything with a ZF transmission in it. Those are know to be high quality, very capable transmissions.
