Think of Solstheim in Bloodmoon.. now imagine that with large mountains, an ashy south coast, and a PC who cannot run nearly as fast as the general Nerevarine could.
I assume you are talking about a Nerevarine with HIGH Speed & Athletics? Because with the default starting stats for Speed & Athletics you run like MUD.
The Skyrim PC runs WAY faster than the
initial Morrowind PC.
Still, I get what you're saying. As long as you can't run across it in 2 minutes, that's fine by me (I really hope I didn't just perfectly estimate how long it takes to run across it

)