I went from 30" carni's to 32" K9's. I would never go back to 30"s. I do a mix of slow and high speed trail riding. I would avoid a full blown clutch kit unless completely necessary. Try an EPI grey secondary spring for $30. That brought my clutch engagement rpms back down to stock range(1850). I haven't had any belt slip at all with the new spring and belt temps have never been an issue yet(I run an Aim gauge).

 

I went up to 30" tires (used) and then bought a set of 32" XTR370's. (Love these tires!)
I haven't touched the clutch, but I did the gear reduction.
We do east coast mountain trails and rock crawling.
Mostly slow stuff over big obstacles.

 

Yes that should work. It is depending on what type of riding you do, I'm going to go 30" and I do trial riding and a bunch of high speed stuff.
And if you do bigger then 30" you are going to want a clutch kit.