How do I get the Hexes to fit Reality?

I'm staring at several maps which overlay hex grids on an outline of Great Britain. I'm trying to work out which orientation, size and positioning of the grid best suits the game. It should be possible to build at least the main historical routes, while giving plenty of alternative choices for players to build or block routes. Certain cities will be key - London is a particular pain because no routes run through it.

There seem to be lots of choices, none of which is quite right. When I get the hexes to fit around Central Scotland, for example, it throws off either the Midlands or the South of England. The latter is particularly difficult because there are so many east-west routes in such a small space and I want to keep plenty of choice in order to make the game interesting.

Of course, I could just map the hexes smaller, but that would make the game much bigger and (presumably) longer. Currently the most likely map has a grid of 13 by 6 or 7, although the northern half of the board is only 4 or 5 hexes wide, so the total number of playable hexes is approximately 75. This is the same number as 1830, so I'm assuming it's in the right ball park for a reasonable game.

I'll fiddle with the parameters and stare at the maps some more, but at some point I'll have to accept that what I've got is the best I can achieve and go with that.