Update:
POCO put a recorder on my meter for 2 weeks. Interesting results. Peak time (6-8pm) the house runs 70-80 amps. Makes sense, everyone comes home from work, laundry starts, dinner starts, everything starts. When the house is running at peak usage, my voltage drops from 122V down to 109V.
That's over a 10% drop. ICC allows a 10% drop for up to 2 minutes. In my instances, drops were recorded in 11-15 minute intervals. We tried a real time recording as well. After turning the oven and kitchen hood on, house was drawing 25 amps. 25amps and the volts went from 122 to 119. 3% drop just running the oven- something is not right.
POCO took the readings back to the office to see what their engineers suggest as the next step. While the wiring is undersized for the distance, I would think a 25a load should be able to run with a 1% or less voltage drop with the current size wiring. To me, this indicates possibly deteriorated wiring or other issue. Transformer is 37kva and only serves my and my neighbors house. My neighbor doesn't think he has any problems so I would probably say it's in the wiring.
Good news is POCO owns the wiring. If it has to be replaced, it's on them at least. Bad news is previous owner at some point built a mud room around the meter. I would assume wiring is direct buried to the meter, which now has a concrete floor over it. Changing the wiring is not going to be easy.