Hello! I've had nocturnal seizures and they are definitely no fun. When it comes to your drivers license, that can change a lot state to state. In the state I'm in, it's simply having to go 6 months without a seizure before you can drive again. Regardless of whether you've had them in the past, if there isn't a big barrier, like the doctor not approving it, then you can get your license back after 6 months. Though like I mentioned, I know some states are more strict and harder to navigate.
On a random note, nocturnal seizures can be so hard in many ways. I 100% knew I'd had my tonic clonic ones during sleep after waking up. My body felt awful. However, I've also had lots of partial seizures and never knew how many seizures I was having in my sleep until I did my longer EEG. It was like 4 days long and they said I had a lot of seizure activity during my sleep. I had no idea I was having one until I woke up and saw tons of nurses around me. My parents that were with me, didn't even realize I was having a seizure until the nurses came in. Nocturnal seizures can be so, so hard in that way. I really hope your friend is doing well and finds options that keep them completely seizure free for a long time!