Perhaps an earlier POD? Have a different Edict of Nantes (1598) generate an earlier and more extensive exodous of Huguenots from France? OTL, the relatively smaller number that left, scattered in several directions. and either became a very secondary body in their new homes, or their New World colonies got hammered by the Portugese or Spanish. A larger exodous may create a larger critical mass of population in an area, which might be more likely to grow long term. That also would provide a draw for additonal bodies of Huguenots from later persecutions (i.e.Edict of Fontinbleau-1685).
OTL, small groups of Huguenots settled in Virginia and especially South Carolina and some later migrated across the Appalachians. The local English authorities extended some land grants to the Huguenot groups
There were also wide-spread, if small numbers of French speaking, French heritage, ostensibly Catholic peoples living along the Great Lakes and Mississippi Valley areas well into the mid 1800's. Many of the foundation explorers of that region in the mid to late 1600's were Jesuit priests, but the French are far less remembered for their religious work in the region than for their other activities: mostly trade. Have some of the Huguenots migrate to that area.