Feel free to do as you want, we all have different levels of what we are able to do and want to mess with when it comes to our animals. In this case, I would bring the babies inside to keep them warm, and bring mom in and assist in the feeding. The way you do that is just to put the kits in between your legs, and let mom sit on your lap while you hold her steady. The babies will likely raise up and nurse, and that is what my experience has been. I am not sure how you supplimented the feeding earlier with this litte guy, but most rabbits dont do well raised on supplimental milk. Its so much easier to get it straight from the mom, and I have never had a Doe not producing milk, although I know it can happen. It only takes 10 minutes or less, so for me this has been a very easy option and not taken too much of my time. I do it twice daily. Best of luck tho, and no one will judge you if you just leave them be either.