Is there always a way to back out of a boss fight?

Dagoth_Rac

Is there *always* an exit from a boss fight if you want to leave and repair your equipment, get better gear, gain another level or two, etc? There are some tough boss battles in this game. I am worried that sooner or later I will find myself in a fight I just cannot win. Since there is no going back to a save game like in other TES games, I am a little worried about losing weeks (or months!) of building a character, just to be caught in a battle I cannot win.
I mean, I want to try every quest that comes my way, even if it is a little above my level. But I want to be sure that if I get in over my head, there is always a way to get back to town and try again later.

Thanks!

Natjur

Hit M, bring up map, pick a new area, and port out

By default the map looks like it only shows the local zone, but you can pick other maps/zone and just find your home zone/city and port out for repair/leveling up

Yakidafi

You can die or run away from bosses and come back later.
I have not met a boss I can not do that with except for 1 in the main quest for AD but not sure if it mattered.