Sweeeeet... I'll throw Uri up onto the Character List. As for how to logically get him out into the IC; Not gonna lie, I'm a little stumped, though I can think of a few good possibilities off the top of my head. 

-As a last-minute addition briefed seperately for fear he might see the Snow Elf and walk out. 

-As a hired gun brought on board by the surface team to even out the numbers.

-Or as an unmentioned survivor of the first expedition, or someone privately hired to find their corpses. 

Of course I'm just spitballing here and am always open to suggestion.