General hercules, Lady TT, I have no idea how Roger Federer will play at Roland Garros.
Physically he is probably fine, but he is probably undercooked a bit in match play which leaves him susceptible to upsets if he is rusty early against the wrong player.
Mentally, who knows what planet he is on after the birth of his twin sons? It might take hims some time to find his mental equilibrium again, maybe not.
I would hope for him to make it at least to the QF at Roland Garros, and then play well in Halle, perhaps a final, and be ready for a full assault at Wimbledon with enough match play, and being relatively rested, he should be tough to beat there. But again, who knows?
Anything more he does is gravy on his plate. He's probably playing more for the fun of it at this point, though he has done some serious conditioning, so it's obviously not without effort to be fit enough to do well. Doesn't seem to be taking his losses in the finals too hard, though I thought he didn't look so happy after his upset to Chardy in Rome. We'll see what happens.
It's a major life change to add two more children to the family, but if anyone can handle it, it is multitasking Roger Federer, with the great help of his wife, family, and friends of course.

He could retire this year, and I wouldn't be surprised, or he could go on till 40 and I wouldn't be surprised either.
Respectfully,
masterclass