I have become very interested in the connection between Caldwell - North Yorkshire (near Stanwyck) and the Caldwell family in Scotland.
By definition it must pre-date about 1250 when Caldwell's were first known by that name in Scotland.
Stanwyck is very ancient (pre-Roman) and I believe it to have been a trading centre. Nearby Barnard Castle was granted to the Balloils by William the Conqueror. The Balloils became Lords of Galloway and also had possessions in the Renfrew/Ayrshire area. As the Balloils were of French ancestry - had lands originally near Caldwell North Yorkshire and later on the Solway Firth and in the area of Renfrew/Ayrshire where Caldwell's are found might this be a dimly remembered legend that gives the "French Connection".
Its a bit extreme but we are all still trying to arrive at a solution to how the very English surname Caldwell managed to get itself so thoroughly planted in Scotland.
The french connection is done to death and I believe it is discredited however I cannot help but think that there may be just a slight shard of truth in there somewhere.
Note carefully that all this would have taken place many centuries before Hugenots were even thought of.
The name Caldwell in England seems to occur principally in areas of Danish influence and occupation. This may be the "Viking" connection.
The notion that they were survivors of the Battle of Largs is fanciful. The Caldwell's were on the Scots side in that battle and were rewarded for it (by implication). It was a very nasty little battle and I doubt if any of the Norse survived (let alone remained as settlers). In the unlikely event of survivors they would have been retained as slaves in the custom of the times.