In the 'Old Man Logan' comic, Wolverine is presented as an older version of himself. His age is somewhat ambiguous, but it's clear he's past his prime and facing the challenges of old age in a dystopian world.
I'm not sure exactly, but there are quite a few issues and related series. You might have to check with dedicated comic databases or fan forums for an accurate count.
Old Man Logan's ending is quite intense. Logan finally faces his demons and brings some closure to his story, but it's not a straightforward happy ending.
The Old Man Logan comic had a considerable run. It lasted for a number of issues, but the exact count can vary depending on different editions and reprints.
Old Man Logan is depicted as a grizzled and weary veteran in the comics. His experiences have left him jaded and determined to survive in a harsh world.