With portals like that, it's kind of iffy on if they are still around. Sure, they aren't around in Skyrim, but Skyrim also isn't the most magically inclined place. They only have one magical college with nowhere to teleport to. It could still be viable, but in this time period, would probably require portal platforms like in Oblivion. I don't know how difficult those are to create. 

Also, I just have to finish references and formatting now.