i've been in situations like that before. when it happens during a work day, i just try to do my best knowing i'm not at my peak. when it happens on a day off, i just ride the lazy wave
usually, though, i'm afraid of messing up my sleep pattern if i go back to bed, so i try to stay awake watching movies all day or something like that.
in general, too much sleep makes me feel groggy, not well rested. not sure if that's the case with you, though.