enough is as good as a feast

too much of a good thing is good for nothing

Too much in the vessel bursts the lid (Am.).

Enough is as good as a feast (Am., Br.).

All sunshine makes a desert (Am.).

Mustn't overdo a good thing.

Nothing in excess is best (Am.).

Too much water drowned the miller (Br.).

Plenty is no dainty (Br.)

Enough is enough, and too much spoils (Br.)

Enough is enough