You should find modest-priced 3C or 4C LED lanterns from common brands including Rayovac, Dorcy, Energizer, Coast etc.
I came by a supply of alkaline C's to use up and found a few 4C lanterns in thrift shops, some older but still good. A number of handheld LED spotlights also use C's, likely to keep size/weight down compared to D's.
You could get C-D adapters and use those cells in D lanterns.
Dave