Sorry I didn’t read the posts about all this but 100AMP in todays standards is NOTHING! It is a potential fire hazard. Especially if the wiring is old.
Think about what we have now that we didn’t have then. Microwaves, 3 TV’s, Computers, printers, bigger fridges, recessed lights with 100Watts in each, dehumidifiers, ect. ect.
I would invest a few thousand dollars and change to at least a 200 AMP. How big is the house?
I do plenty of these and I’ve seen a hairdryer dim the lights in another room.
If you’re drawing a lot of amps, the wires will get extremely hot therefore possibly causing a fire.