Devil's Lake is not one piece; it's several pieces connected into a larger one.
To catch anything, one must really know the spots that catch. And the baits, too--usually, live minnows on a hook.
Mid-spring to early summer is best. The bites are winding down now. Active anglers might still be able to catch some at night or at some parts of the lake. Can't be as hot as in the spring though.
Is it worth driving 10 years each way? Well, any trip is worth taking.