A straight cord like that can dissipate a lot of heat, and it is better if it's 240V, as even a 100' cord won't drop the voltage enough to matter, and the heat produced is like 1 watt/foot. That could be a problem with a 100' cord coiled tightly in a insulated situation, then it could start to heat up the cord. A 120v long extension cord is more likely to cause issues due to voltage drop and more heating.
We have something like a 240' run to our submersible 220V 1hp well pump and its not heavy wire. 14g I believe. Running the same distance on 110V would've required some large gauge very expensive wire, as I was thinking about being able to run the well pump with a small 110V inverter generator, but voltage loss and resistance gets too much at that distance.