Modern Millie

How should the character of Mrs. Meers from Thoroughly Modern Millie be portrayed?
Is Mrs. Meers supposed to be more evil, or funny? Angry and enraged, or cheerful and creepy? Any tips on playing her well?
I know this is largely up to interpretation, but I would love to just hear some opinions from you guys!
Do not try to stereotype her. A real actor finds out how the play would end if their character wrote it, and works towards that.
Having said that, Mrs. Meers is a cartoon villain, but a sinister one. She should be very large in her polite inconspicuousness and brevity. This is true of her “Asian” persona. As Ivy Clumpett, she should be quick, broad and cynical. Resist the temptation to go too far, but play with energy.
Thoroughly Modern Millie