After finishing the game (and half finishing a few more times--a huge world like that deserves to be experienced in a few different ways) I remembered an old post talking about how much adventure fits a 6-mile hex. If you don't want to read the whole post (do it, it's interesting), at least consider this excerpt:
The region of Skyrim is roughly the same size as the region covered in Oblivion, which is around 16 square miles in area. Really? 16 square miles is 4 miles on each side. My 6mi hexagon obsessed brain immediately replies: "You realise that's all on one hex."
Now let's see this map (click it to see it in full glory):
How many encounters? It's over 300. Can you fit them in your 6-mile hex. In theory, yes... ;-)
However, I disagree with the statement saying this map covers a 16 square mile area. Why? Because if you consider the time spent in game (using the game clock, which runs 20 times faster than reality, if I'm not mistaken), you'll take a lot of time to wander from one point to another. I won't invite you to track the time to travel on foot from one city to another, but there's a convient way to track the time spent: fast travelling.
When you fast travel, the game adjusts the clock as if you walked from here to there. Now, if you convert this time spent travelling to a rough 3-mile per hour walking speed, what do you have?
*scribble scribble math math scribble*
If my math is not too far form the real result, each parallel line on that map is 7 miles apart. So, the map has a size of 84 miles per 56 miles, or an area of 4,704 squared miles.
But bear with me here. Instead considering a 7x7 square, in order to simplify the math, why not consider each square to be 6-miles wide? And since we are simplifying things, those 96 squares could be 96 hexes... 6-mile hexes.
So you have a 6-mile hex map measuring 12x8. 96 hexes full of adventure.
And what about hex density? On a quick glance, I'd say you have 3 to 7 locations per hex. This is still huge when comparing with my pale 1-in-6 chance of an encounter per hex, but at least it's easier to deal with than trying to fit 300 locations on a single hex.
Are you prepared to stock your hexes with 1d6+2 encounters per hex? I'm not. But maybe I should re-think the way I populate my hexes.