Live in CO as well and about 8k miles deep on my 15' TEP bought end of May. First SUV, let alone 4Runner and bought with, what seems to be, similar intentions (fun on the weekends, reliability on and off the trail). I had weathertech's I brought to the dealer when I picked it up (I bought from Mtn States, as well.. noticed your front plates). I put 275 KO2's on after 200 miles going back and forth between Coopers, Grabbers, all of the mentioned. No rubbing with 275's, drive a significant amount on road during the week and several trips on trails from here to Aspen and in between since purchased. Barely notice road noise difference (although still young tires 7,800miles), and an obvious more "grippier" "stiffer" tire.. which is what I wanted. I sold the Dunlop 265's that came stock for $460 on CL within 4 days (so there is a demand). The KO2's set me back $1k after taxes with full tire protection at Discount Tire - I thought that was fair, especially since it's a new tire they had to locate from another store (they price matched Tire Rack, don't let them say "that doesn't include shipping", because TireRack has a warehouse off of i-70).
Couldn't be happier. No other "mods" yet, but I did purchase a Yakima Skybox (so we can sleep in the rig, if necessary, during camp trips) and also better protection for skis. And Thule T2 bike rack for the 2 wheel rigs.
The pine beetle has seemed to kill all money trees, as well, so I'll probably have to slow down for now. However, next up will be sliders, stoked on Budbuilt at the moment but that changes every 24hrs haha. Going from there I will hopefully go with a Toytec 1-3" adjustable lift (or something of the sort) and some skid plates.
Hope this helps, see ya out there!