"No bathtubs." Don't think he doesn't see that reluctance, Hiro, but he sees the concession too. Tadashi never wants to make Hiro too uncomfortable if it can be helped, but at the same time... they'd be doing something really important, and he's sure they can arrange things well enough for everyone to have their needed space. Tadashi's good at figuring out how to live in small spaces.

"I'll take responsibility for everything. I know you guys are busy with supplies and getting things up off the ground."

Something Tadashi thinks he should probably be more involved in, but the other two always seem to have things under control, and someone has to be around to hold down the fort when they're out, right? (He's just going to keep telling himself that that's why he hasn't gotten more involved. Yup. And also it has nothing to do with Callaghan and Hiro not wanting him involved in trips to the black market, nope.)

"But we'd really be helping, so if you're both okay with it..."