Janeway has been brought back to sweet sweet permanent life in the latest novel.
The post Endgame books (referred to as relaunch as opposed to books set during the series) are quite good IMO. The vary in quality but there are some gems there and the story can be engrossing. The most recent writer for them who posts here sometimes is excellent. If you want a list of them just let me know, they are one long story arc(s).
Admiral Janeway appeared in First Contact for about 6 seconds. Otherwise we only have our imaginations..
And would I like to see Kate Mulgrew in the role of Janeway 25 years later?
YES YES YES I would.