The only thing you have to watch out for is how well your system manages maps of that size. I have a laptop with just 4 GB RAM (very tiny in comparison to some of the systems in use by other members), but I get around this by using layers that are only as big as I need them to be. For example, if I have a 10,000 pi square map, that doesn't mean the layer I have the river on needs to be any bigger than the width and breadth of the river

That way I've been able to have as many as 40 layers on a map that size, despite the limitations of my hardware