I don't think that Ennis could ever go back to being the same after Jack's death. It is remarkable the things Ennis did post-Jack that he would've never done before. Calling Lureen, traveling beyond the coffepot to LF, and when there laid himself so bare to two strangers, Jack's parents, that he was their son's friend...and lover. Watched the film the other day for the umpteeth time..( I've lost count), I just hate the fact that Jack had to die.
For years Ennis hid his love from others due to fear, shame, whatever, but now he must face those fears head on. Guilt? yes, regrets? certainly, but the shirts were symbolic in their own right of Jack's continuous love for him. Ennis imo sought to honor that. I feel he felt obligated in some way to find redemption in the face of what was, and guilt for what he could'nt change. Jack was gone, but he left a message in the way the shirts were displayed and Ennis finally "got it".
Breaking it off with Cassie, putting numbers on the mailbox, and deciding to attend his daughter's wedding are all evidence that Ennis had seen the light and realized a higher level of exisistence, more open. It all came together for him in Jack's closet. He could finally shed his old ways and embrace love and life. He came to LF seeking to have Jack's ashes to spread on Brokeback..." like his wife said he wanted", but I feel Ennis had his own motivation for wanting them spread there of course. It was where he and Jack discovered love.
Mr. Twist denied him the ashes, but Mrs. Twist led him to something much more valuable than anything, the shirts, he could take them home, display them in his closet as if he finally could live with Jack after all. At least in a synbolic way. In any case, he had the spirit of Jack's love with him, and in the face of that, he could live a life free of the fear of love , finally accepting that not only was he loved all along, but that he could love whom ever was left of those he cherished. Jack taught him that imo. Thanx.