I've used medleys at the end of an evening quite frequently, usually with no walk-through (maybe some mention of a key move), sometimes with no advance warning (and occasionally without advance planning!). Usually I use just two very straighforward dances, with the idea that either of them might be just a little boring by itself to go full length, since it's mostly the experienced folks left, but that the crowd has run out of the mental gas to really do anything much more challenging. The dances are simple, but the dancers feel sufficiently challenged by there being little or no walk-through, and the change in the middle is another pick-me-up. The dancers haven't struggled, but they finish feeling like they've accomplished something.
I agree that you need to be cautious about similarity between the dances. If they're too similar, it's confusing and probably boring. If they're relatively simple and mostly different, you won't need to call too much, except to remind people what comes next after any similar moves. If you don't have to call much, there's no conflict with the band and their "hot finishing tunes". ~ Becky Nankivell Tucson, Ariz. and Long Beach, Calif.
