I've created some conversions for the Iron Kingdoms. Already posted these over at the UnearthedArcana subreddit, but I figured there might be a 5E community on these boards, too.
Things I've banned: Rangers (the Unearthed Arcana: Kits of Old has a viable Scout alternative), Eldritch Knights, Arcane Tricksters, Way of the Shadow, Way of the Four Elements, and the Great Old One Patron.
Restricted subclasses: Path of the Totem Warrior (must be a tribal member of an ogrun or trollkin community), Oath of the Ancients (must belong to the Circle of Orboros; the tenets of your oath are revised; you are are to respect and defend nature from the encroachments of civilization; in addition, replace every mention of fiends with constructs for purposes of determining the effects of your class features), and Dragon Bloodline (you must play a blighted character; as a carrier of Toruk's blight you can choose either acid or fire as your damage type; as a carrier of Everblight's blight your damage type is cold).
Spells: Resurrection and true resurrection do not exist; raise dead and reincarnate are both 9th-level spells; teleportation circle does not exist and all other teleportation spells are restricted (if a wizard character wishes to learn one of these rare spells, he or she must copy them from a scroll or tome).