In my Dutch TL, I had a successful Spanish Armada invasion occur in England. As the English government collapsed following the capture of London and Oxford, Scotland took advantage of the situation and temporarily moved south, occupying Cumberland, but ceded the territory to the new Catholic government in London after the new government had settled in and begun raising a new army. After the collapse of said Catholic English government in the 1630s, Scotland moves south again, re-occupying Cumberland and this time not ceding it to the new Protestant, Republican government in Endland.
Also in the 17th century, Scotland begins to develop several small colonies in the Americas. Initially it merely establishes a foothold in OTL Nova Scotia (creative, no?), but participates in the scramble for South America that was a result of chaos in Iberia (and a failed Portuguese revolt), and secures for itself new bases along the northern coast of Brazil, up to the mouth of the Amazon. Of course, it eventually loses those colonies to France after the Huguenot Bourbons decide to break the Auld Alliance and side with Republican England against Scotland, but it was nice while it lasted.