Don't push your luck. Impellers die of old age or running dry. I had to tow in Dick Rose (as in international rules commitee and dealer for his own boat brand) for a probable bad impeller. The spare doesn't weigh any more than a bottle of beer. If you can't change an impeller you better be able to paddle home. I am a retired marime mechanic of 40 years and am a firm believer in self rescue.
