As long as they growin'... let them grow. Some gardeners do plant in the fall to overwinter for early growing.

Hard to guess but maybe there was a problem last year in this spot. Disease? Poor drainage? Not enough sun? You can let them grow and see what you get. Or try again or plant something different. Your decision.

I always leave tiny ones in the ground when I harvest and always get a lot that come back. I saw potato scab last year for the first time likely because of this. I have done it for at least 6 years.