refrigerating cooked waffles
It is certainly safe to keep them refrigerated for a few days, but you will probably get much better results by freezing them.

The cooked starches will re-crystalize if you refrigerate them, making them hard and unpalatable--this is one of the major modes of staling.

By freezing them, you reduce this effect.

You can then heat them directly from frozen in a warm oven to use the left overs.