The way I see it is that Cooper and whoever was inside either of the lodges at the end is trapped and totally fucked. Audrey, Coop, Leland, Laura and anyone else visible in the final scenes are essentially garmonbozia farms ( the literal manifestation of pain and sorrow that the evil spirits sustain themselves with, shown earlier in the series as creamed corn , lol Lynch ).
I interpreted every location Cooper was in after Bob got punched to death ( lol again Lynch ) as part of the Black Lodge. He goes to the motel with Diane in one car and leaves in another the next morning, no one else visible on the roads, zipping in and out of different times, dream like details of nonsense "430 miles" and so on. Cooper tried to save Laura but ultimately could not, they are the Black Lodges playthings.
Half way through season 3 during the nuke scene, the white entity thingy I presume is "Jowday // Joudy // Judy " barfs out Bob and zillions of other evil seeds like its nothing. I assume she is the white ghost that, apparently, can literally do whatever the fuck it wants at any time, hence the symbol on Hawk's map being something that "you don't wanna know about". Judy can manipulate time, inhabit people at will permanently, cannot be contained, studied and maybe even seen without it affecting the viewer. I'm not certain of this but I think Andy was the only person in the entire story that saw her and did not have his soul ripped out of his skull, or set to burn for eternity, or was put in a demon tea kettle, or had his throat bit open, or raped a million times by his dad so his suffering soul could be converted into creamed corn for a demon midget to sloppily eat it. ( oh you, Lynch )
After waiting so long and personally really hoping Cooper could escape and have some sort of good ending, the scene of him seated in the Red Room was BRUTAL. He sees it coming, too, that superimposed view of his face is not a static image but what I believe is him realizing where he is in real time. I must admit that despite how shitty his fate was Coop managed to save quite a few people directly, like Jane-E and Sonny Jim, and probably thousands indirectly by stopping his doppleganger. Evil Coop was filling graveyards everywhere he went, so there was some measure of victory for Cooper. In the final scene we are led to think, 'yes!' he went back in time and saved Laura! Oops nope they're just in hell, sike! I believe that is Lynch's message, evil is a giant immutable thing that will crush us all someday, so we might as well just valiantly struggle against it by say enjoying French hookers or building a kid a cool gym set. Yay.
Lynch did to the audience what he did to his characters, make us wait and wait building up hope that Cooper could somehow stop an increasingly complicated evil force and then he smushed the hope. Well done.