I don't think you'll get any trouble. The licensing violation is enforced by DCP, not having the license. The town would have to turn you over to DCP. I don't see that happening. Licensing is 20's in the CGS. I had a hard time getting DCP on the phone last time I tried. Their email reporting system I would guess is more than two years behind. Pretty sure I've filed old stuff that is still in the hopper.
The town enforces building codes adopted in CGS 29-252. 29's are the Public Safety statutes. If the town gives you trouble their jurisdiction is the NEC. It is a permit required job but "any person" may pull the permit in Ct. Who does the work, is where you need the HO exception to the licensing statutes. No license needed to pull the permit.
The HO permit with the nephew doing the work, I would guess that's one of the existing conventions that the town (should view as legit or more legit than all their other troubles).
The town will show no sympathy over trying to qualify with an out of state license, but enforcement for that is DCP, who does not return phone calls. The family member who also has a license from another state should get some town sympathy, but if you tell the town you're doing the work, they could tell you it's a violation (enforced by DCP which is not going to happen).
Have the aunt deal with the town and you deal with Eversource, should be no problem.