Will female guppies be better off without male guppies?

Female guppies will do fine without any male around.

If you absolutely want male guppies amongst the females, as a general rule you need 2~3 female for every male. This rule is for the purpose of not stressing each female guppy too much when there are more than one female for each male to chase after. If you have more male guppies than female guppies, some male guppies might get aggressive toward each other when they compete for the same female.

Guppies are known as "million fish". They will breed and breed if there are both male and female in the same tank. However, I wouldn't be worried of overpopulation unless you have a large tank with too many hiding places in it. The adult guppies will eat their own fry to keep their population in check.

Furthermore, from your other thread we have learned your tank isn't very big and it isn't fully equipped to sustain tropical fish. Until you can get your tank set up properly, please resist the urge to get more fish.