The Nissan Path

Should I stick with the current 255/65 R16 or go down to a P245/70 R16. (not even sure if it will fit on my current rims)

According to the tire guy, it's cheaper and it's a better idea to go with a narrower tire profile in the winter.

Seems to make sense but what do you guys think?

Your tire guy is right, narrower tires generally perform better in winter because they can better bite through to the road instead of ride on top of the snow. But consider that 245's are only 10mm (~2/5") narrower than your stock 255's. You could go to 225/75R16's and give-up 1/2 inch of ground clearance, or 235/75R16 if you can find a tire suitable for your conditions. All of these sizes should fit on your 2001 Pathfinder's OEM 16x7 inch wheels.

Thanks very much for the info Mark ! Very much appreciated.

Mind the LOAD RATINGS of the tires you +/- size.

That's the TRUE value of any tires capabilities with your vehicle.

But YES -- slimmer and taller is typically the conventional wisdom on snow tires. Just did the same with my Maxima.
I found that slimmer and taller was SUBSTANTIALLY cheaper than the OEM size also, which was a bonus!

If you're going with a smaller RIM - make CERTAIN the wheel has enuff offset & inner diameter to clear your Brake Calipers!

I just threw 140lbs. of sand in the back of the PF for the winter, and it made a HUGE difference in both 2wd & 4wd performance.
Cost me $7.

gr