sleeping through the night!

My baby girl is a month old and she just recently started sleeping through the night (thank god) but my question is, do I wake her every 2-3 hours to feed her? During the day she feeds every 2-3 hours so should I do that st night as well. If I let her sleep through the night, how many oz of formula should I give her once she wakes up? She usually drinks 2-3 oz during the day.