Be aware that NIPSCO will require you to have an inspection before they reconnect to your new service. That means the inspector will be looking at your whole house and require you to bring the entire house up to the current code.
Nobody is installing 100 amp services in homes anymore. The cost to upgrade to a 200 is minimal as far as the panel goes.
Find three contractors you feel you can trust and have them give you a written quote that states they will bring the home up to code and pass an inspection.
I don't think my contractor called for the unhook, or the hook up.
Last payment for the wife's car this month