just an idea for a then great game mechanic, i'll explain:
Ether a Quest from Neloth to help bring them back (Could be a dwemer device or telvanni magic)
OR (my favorite idea for it:
Spoiler
After beating the DB main quest you acquire dragon riding to some extent, would it not be a great thing to do by making you go back to Skuldafn (gate to sovengarde) and ask/fight Shor or Tsun in order to bring them back
tell me what you think, I would personally have loved a growing battle between the player and Miraak, Like a bond Villain seems to some how make it personal with Bond and pretty much beat him but then in the end Bond finds a way (weird reference i know)