Actually, it's only just now, as she says that, when Sokka realizes just how monstrously bad of an idea this all really is.

He blinks at her, then looks over, abruptly anxious. "Uh, Steph," he begins and - fails for words.

Instead, he lifts the tent flap for her to see.

The igloo can comfortably fit two people... if they don't try to stand or move around too much.