I have been thinking about this a lot lately, after starting at my current job. I am used to Repositories, they go the full IQueryable path using just bare bones repositories as you suggest.
I feel the repo pattern is sound and does a semi-effective job at describing how you want to work with the data in the application domain. However the issue you are describing definitely occurs. It gets messy, fast, beyond a simple application.
Are there, perhaps, ways to rethink why you are asking for the data in so many ways? If not, I really feel that a hybrid approach is the best way to go. Create repo methods for the stuff you reuse. Stuff that actually it makes sense for. DRY and all that. But those one-offs? Why not take advantage of IQueryable and the sexy things you can do with it? It is silly, as you said, to create a method for that, but it doesn’t mean you don’t need the data. DRY doesn’t really apply there does it?
It would take discipline to do this well, but I really think it’s an appropriate path.