What happens if I leave a quest only area?

I mean the area where you have a door icon with 24 hours counting down.

Since getting to Kaifeng I have been pushing through the main quest with my upgrades not keeping up with my solo realm and I have been managing so far, though I have died to Dao Lord more times than I'd like to admit, but I am currently at the God of Avarice and it has become evident to me that I am too underpowered for my meager skills to bridge the gap, even after reverting one solo realm down he is chunking me for up to almost a 4th of my health with regular, parryable hits (and I'm running stonesplit so I have a chunk more health). The furthest I've gotten was removing all his health in phase two but he saved himself by summoning coins and then killed me with the dual sword beyblade move (I especially suck at dodging that move).

I am also running short on potions so leaving the area is inevitable anyway unless I achieve some enlightenment and no-hit him.

What happens if I leave the zone? Will I be able to come right back or will I have to repeat the whole break-in sequence?