New to site

Hi Guys, New to the site and just purchased a new 2015 700 Grizzly EPS SE. I am from Ontario Canada and will be mostly using my bike in the winter for ice fishing and occasionally plowing. I have stock 25" Maxxis tires and find the whole tire size, width and clutch kits very confusing. Ideally I would like to maximize my performance in snow/slush. The dealer suggested I don’t go bigger than 26" but I’m hearing conflicting things about when I need a clutch kit and when I don’t. Any help will be greatly appreciated.

Thanks and look forward to contributing to the site(might just be questions for a bit)LOL!