Yes but how much money did spain get from the south to begin with. Almost all income from anything other than the islands would not exist here. I expect the islands would go to who had the better navy at the time. I expect africa and asia would also be very important in predicting how things would go down.
I'm doing some research on the territory the respective empires had at the time now. Hopefully it should give a good idea of who would be left with what power.
EDIT:
Now i've spent a few hours going over the maps and history i think I've got a pretty good idea of how i'll set out the history.
The majority of the information i have used to work this out has been gained in the last few hours with the remainder coming from my general knowledge of the period. If anyone has a greater understanding please point out any problems.
There are pretty much four big contenders here: The Spanish, the Portuguese, the English and the French.
Now i'm going to set it out in several stages:
1) Discovery - lots of failed expeditions until word gets back around 1600.
2) Initial colonisation of outlaying islands - Period between 1600 and 1700
3) Colonisation of the mainland - 1700 - ~1750 when game is set
I've described the first stage earlier but i need to amend that since i now find out that Columbus never even reached the mainland until his third voyage. This doesn't change the result because the map i'm imagining is of a continent similar to north america (minus mexico) shifted north a bit with a set of islands roughly the size of the Caribbean/Bahamas islands along the east and southern sides. So this means Columbus died a horrible death at sea or was forced home. The end result is that discovery is delayed by a hundred years.
The balance of power is now very different to reality. Spain and Portugal loose their massive advantage over France and England. There is overall less colonisation by these countries but there is more in africa and the far east. When the wolf continent and the islands are discovered there is colonisation of them but it is much fairer with England and France having the majority due to the islands being further north. War in europe dominates the politics at this point with the main combatants being Spain and France. This is a fairer fight but still means England gains the largest share of territory in the west (but not by much as no one really has much interest) while Portugal along with the Dutch gain the most in the east.
The wolf continent at this point does not attract too much interest. The furs and the hope of precious metals keep a dozen or so costal colonies running. The islands are too far north for any significant sugar or cotton plantations and so have pretty small populations.
Towards the end of the 17th century things change drastically though. Slowly (due to a lot of people dying as soon as they leave the colonies) it emerges that there's a lot of valuable metals on this new continent especially silver. This brings a new interest and the number of colonies increases rapidly. Soon though the casualties mount and progress slows to a crawl.
At this same time though the superstitions of werewolves from Europe and the silver thing have been incubating. Silver is expensive though and so it's use against the wolves is mostly in jewelry which has very little effect when it comes to increasing survival chances, however successful hunters and explorers are investing in silver ammunition and the occasional blade. Due to silver not killing a wolf outright it is hard to verify the belief and again as silver is so expensive it's use as ammunition for soldiers is non existent.
Soon after the discovery of large qualtities of gold and silver mines start popping up. It doesnt take long for people to notice silver mines go up and stay up much easier than others. The soldiers defending these silver mines would soon start using at least a certain percentage of silver in their ammo and at this point the evidence begins to snowball. Soon with the cheap silver hunters are making wide use of it and so then individual soldiers followed by entire regiments.
The countries begin a desperate grab for silver mines and equip their soldiers with as much as they can afford. Conflict breaks out across the region adding a new front to the war started in europe with the waning spanish forces joining with the French to battle the rising threat of the British and their Portuguese allies.
It's a few years after the conflict really takes off in the west that the game starts although i think worldgen could just about handle it from the discovery of the precious metals. I'll need to experiment with the new version to see what i want to do.