If your lawn has become sparse and patchy, you definitely want to overseed before the weather gets cold, but if you have a weed problem, this should be addressed first. You may not be able to use a weed-and-feed fertilizer, because these contain a pre-emergent, which can prevent both weed and grass seeds from germinating. Instead, use a lawn weed spray to target weeds in your lawn. Give it at least a week to kill weeds, and then pull up the remains of any large, broadleaf weeds like crabgrass that would prevent grass seed from reaching the soil.
Overseed and fertilize at the same and take care to give the new seed light watering daily until it germinates. Also, instead of using a winterizer or starter fertilizer, use both, mixing them at a two-to-one winterizer to starter ratio. This mixture can give the new seed the potassium and phosphorous it needs to establish itself quickly, as well as provide the entire lawn with slow-release nitrogen that can help it survive the winter.