What are some tips or tricks on how to end a novel when you're just not feeling the story anymore, but don't want to give up on it?

Well, how did you plan to finish the novel when you planned it?

Presumably you know that a novel isn’t just 80–100k words randomly written down? There’s character arc and plot arc and all that, so if you’ve worked through both of these then the novel is finished, and your pre-planning will have ensured that you’ve paced the novel correctly so that all the ends are tied up neatly and the story is properly finished.

So then you stop. Writing a novel isn’t just ‘telling a story’, it’s showing how the actions affect your characters and how it changes them. If you think established novelists are just writing words until they get bored, then I suggest you go and look at how some of your favourite novels are structured.