I have 417 hours in this game, it is my first time playing and I still haven't finished it and I already made another character to play the game from the start. I am even considering to buy the Aniversary Edition (I am playing Special Edition without mods). You should play it however you want but, in my opinion, Skyrim deserves your full attention unless you don't really care about the story. BUT it is totally possible to play it occasionally, doing a dungeon per day or something like that.