I got tenure (last year) after having a kid (two years ago). We do have family in town, which as you say is a big help. We both took leave, and I basically did

I got tenure (last year) after having a kid (two years ago). We do have family in town, which as you say is a big help. We both took leave, and I basically did not do any research during my 12-week leave. I did meet occasionally with my students (they don't go on leave, after all). So it is possible, and I strongly encourage men (or anyone who isn't the birth parent) who are on leave to do this -- the birth parent is much more constrained and this difference has been shown to lead to measurable difference in outcomes in the future for their careers.