Modders are here for you OP!
Beyond Skyrim is a massive multi-team mod project that opens the borders and brings Skyrim's neighboring provinces to life. No longer will you be turned back at the borders of Skyrim, but you can travel onwards to the lands beyond.
Cyrodiil's team is furthest along in development, with the Bruma pre-release available on PC and Xbox right now, larger in size and with more content than the official Solstheim DLC. Here's an 8 minute recent dev diary covering progress from all the teams (Cyrodiil, Morrowind, High Rock, Hammerfell, Elsweyr, Blackmarsh, Roscrea, and Atmora):
Wow. This is fantastic. Thank you for sharing!