Diana, Generally you will have a lot more legroom (and width) than on a plane. Your husband should have no problem. Additionally, standing up, walking around, going to the bar car to get you a coffee and croissant will be a lot easier than in a plane.
face-to-face and face-to-set-back will have roughly the same leg room. But face-to-face you can stretch out your legs between each others if you want.
For some photos of TGV-Lyria, including the seats, see here: http://seat61.com/lyria.htm
As you can see you have a lot of space, and a nice table between you.