I knew one person that stopped both successfully on the same day.
I know many others that simply couldn't do it or relapsed from both addictions.
We were told point-blank in outpatient rehab that it was a very bad idea to stop smoking in early sobriety. The withdrawal effects are very real from nicotine, and the two can amplify each other.
I had started smoking in rehab after 9 years and got back to a pack a day. I quit about 75 days in a few weeks after I started Wellbutrin. I just kinda lost interest so I went with it.
Smoking is a terrible addiction, but alcohol is far worse. One step at a time.