Speculation on if it were... (SPOILERS)
Lilly at the ski lodge. I would think that maybe she would be even more hardened, but still slightly emotional and bitter over Larry's death, and possible a little bit remorseful over her actions that led to her being separated from Lee's group.
I can't help but wonder how she'd try to explain killing Carley (and stealing the RV) to Clementine. Personally, I think that she would probably not want to talk about it, but maybe admit that she made a bad call.
What do you think might have happened if it were Lilly at the ski lodge and not Kenny?