Packraft sizing with a fat bike

Hi, I’m just getting started with packrafting and plan to do a bunch of it with my fat bike strapped on top, plus gear. Most of my trips will be in AK, where I live. Any recommendations on what size boat to consider? I’m 5’7" with a 28" inseam and am considering a Yukon Yak. Is it usually recommended to go one size up from the regular sizing parameters? or more?

a small boat works fine. i am exactly your size and i have the old style alpacka. have done some class 2/3 with my pugs strapped on. no worries

A Yak sounds about right. Though you’d probably be best in an Alpaca without a bike, I think you’d appreciate a bit more room up front when bikerafting. I best fit into a Yak, but use a Llama for bikerafting (I ride a 20" Pugsley). I should mention that I don’t use a spray deck, so it’s easy for me to fill the excess room in the bow with gear and press my feet against this. This helps provide good stability and performance while giving my knees and paddle strokes more room compared to the Yak.

I’ll add that - while I don’t want to discourage you from getting a new boat - I do prefer the pre-2011 boats to the newer ones for bikerafting. Their bows are boxier and fit my bike better than the newer boats. However, your bike is hopefully smaller and will likely fit on the newer bows better than mine.