One of my professors back when I was law school said she exactly what your planning to. It was extremely hard, but she did do it. Law school is a very big commitment especially if you have a 2 1/2 hour commute though. Any plans to move closer to the school? I think it CAN be done, but realistically a 2 1/2 hour commute combined with raising a kid could be to much. Plenty of people can go through it with kids, but tacking on a 2 1/2 hour commute especially if that is only one way is really pushing it.
The four hour commute option might be better if the grandparents are there. The odds are you will probably end up spending extended nights wherever you go so the four hour commute option might be better.
I hate to discourage people, but you an extensive commute and raising a young child combined with first year is tough. What schools are you considering by the way I only ask, because I recently coached a mock trial team at South Texas Law School and I have to say I loved the place. I had never heard of it before, but I really loved how everyone treated eachother there.
Well good luck, and anything is possible, but 1L is no joke. The rest of it kind of is, but first year is tough. Good luck to you whatever ends up happening.