those are two VERY different campers. if you're wanting to get off road i'd stay away from the triple slide. too many moving parts, too heavy. newer 1 tons have payloads over 4300 lbs depending on your configuration so that would give you 1500lbs of cushion on that northern lite.
i've been on plenty of roads here in colorado where i took a big camper on singles that i wouldn't take a dually. rocky and/or rutted single tracks that a dually just can't line up with. also, CO is exceptionally rocky. can you make it down lots of FS roads here in CO with a dually? sure, but you will find some you can't make it down for sure. it's a real bummer to travel to some place only to be turned back and have to find another.