When? He went to a 5 setter vs Nadal. He wasn't even close to winning that match let alone the tourney. His best performance is round 4.
The best record for a 195+ player at RG has to be Delpo making the semis in 2009 and going to 5 vs Roger. That's as close as anyone has gotten. The court isn't skiddy enough for serve to be the sole winning factor (through high bounce) . Any possible candidate has to move effectively laterally and sidewise. The player who comes closest to such a profile sadly happens to be a mug at Slams. (Zverev). If he is able to improve, he's the most likely player to win.
Also, neither defence botting nor ball bashing can alone win it on clay. Slow incremental point construction is a must. Medvedev is a serve defence bot, which is why he fails miserably on clay.