Really need to smoke a brisket overnight if doing it at 225-250 degrees. Most pellet smokers or charcoal can be loaded up about 10 pm, and get up and refill at 5 am or so and have a bloody Mary. Usually wrap around 7-8 am and continue until probe tender 202-207 depending on brisket around 2 pm, then pull and cover in old towels in a cooler until dinner time and it will melt in your mouth and still be hot.
An almost as good in a hurry is 300 degrees and you can start at 8 the morning and same procedure to be ready to rest by 3 pm or so. It'll just not have the same level of smoke and bark but still very good.