Solid.

Nothing is. When things are this dire, and supposing you are trying to make a fight of it, then you look for anything that gives the opponent an opportunity to stuff things up. In this game, though, White didn't accept any of those, rather slender, chances! No game is so winning that it can't all be thrown away with one or two ill-considered moves. White kept his head until the end, and for that: Well done!

41.f3 was also worth considering. I like the text move, though, as it places greater distance between rook and King. After this, White could just about play exclusively with his pawns on the Q-side (beginning with 42.c4!, after which his pawns can not be stopped), reserving to essential defence any K-side play. The Rook on e8 cuts the Black King from intervening on the Q-side, so Black would be reduced to mounting a hopeless attack on the K-side. So there was no real need for the Rook to chase after the Q-side pawns (though to be sure that is an option).