When and Into What Should I Repot this Paph

[JKeys]

This is a multifloral paph, paph michael koopowitz x gigantifolium. I got it in February of this year and it started putting out a new leaf not so long after that. The leaf is still growing but progress is a little slower. I am wondering when to repot and into what size pot? I could repot it with new media into the same size it is now, or move up to 4 inch plastic pot. The roots seem healthy although the media seems a bit old. Thanks!