I have just begun the Season Unending quest, and I have a question I have not seen covered on the interwebs.
I have yet to begin any civil war quests at all. None with Imperials, none with Stormcloaks. I am wondering if completing Season Unending is going to mess up the experience I would normally have with the civil war quests, if I had done them before having been assigned Season Unending. If I finish the main story line, do the imperials and stormcloaks go back to normal? Should I go back to a save prior to having been assigned this quest so I can do the civil war stuff?
Thanks in advance.

Nah. No real spoilers, BUT it can result in a Jarldom or two changing hands. If you are currently pursuing a Thaneship, it might cause issues.
The only bad thing you can do is to try to do the civil war and the MQ at the same time. Finish one then start the other is the safest way to proceed.

Excellent. Thank you.

I was hesitant to continue on one save when I might have to revert, so now I can get back to feed the addiction.