I retained my NJ driver license and NJ registration for my vehicles after moving to PA.
Legally, "they" say that I have 30 days to get a PA DL, but that does not work for me... NJ did away with required vehicle inspections for diesels and so all I have to do is renew my NJ DL every 3 years and pay the yearly truck registration on my '04 Cummins equipped Dodge Ram 2500.
I actually had never registered in PA to vote, until this year's primary because I now own property and pay property taxes in PA.
Voter registration in PA is very clear to say that to register you can use a commonwealth of PA issued DL, or PennDOT identification card, but if those forms of ID are not available to you, you just need a utility bill with your name and address, and the last 4 digits of your Social Security ID number. You can register to vote online... and OH MAN IS IT INVITING FRAUD... BIG TIME.