Hello and welcome to the RTA forums !

I can't help with the holiday traffic question and although you don't say where you are actually starting and finishing your trip, if Google maps is telling you it's a 30 hour drive, you should know that it is already a 3 day trip ! Mapping programs do not allow for 'real world' driving which includes traffic and construction delays, human needs like needing to eat, rest and go to the bathroom, nor allows time to fill with gas.

Travelling 500-600 miles per day is 9-10 hours of driving with time for these limited stops. An hour in the morning to get ready and have breakfast and an hour or 2 in the evening to unwind and eat and you already have a 12-13 hour day. Newton MA to Dallas TX is 1750 miles and should not be attempted in less than 3 days, if you come across bad weather you will a little extra 'wiggle' room, but not much.