Wow 30 players! That sounds like a pretty epic campaign. I'm sure that you'd get quite a bit of support for a game like that should you wish to try it. Honestly, I've never had any trouble converting Pathfinder to 5E but I've never been one to faithfully follow modules anyway. I often take pieces of some modules and slap them together with others to form a more interesting narrative. I think that you could adapt Kingmaker to 5E. How much work it would take depends entirely on you. You could easily just reskin a few of the more unique monsters to fit the CR of 5E or you could pour through the adventure path and try to convert them via the rules for creating monsters on page 274 of the DMG. That would be much more time consuming of course but the great strength of PBP is that you have plenty of time to prepare while playing!
Last edited June 21, 2017 2:27 pm