OK, here's a rough idea of what you're faced with. A lot of winches come with 2 AWG wire. 2 AWG wire carrying 300 amps and 12 volts, you would have a voltage drop of nearly 20% after 25 ft., obviously you don't want that. Best to plan for max. amperage ever, not typical load btw. Also, most winches have a momentary initial current spike on start-up that is more than the draw on a pull. But I digress - in our example, if you increase your wire gauge to 1 AWG, your voltage drop at 25' would go down to 15%. 0 AWG, it goes down to 12%. -1 AWG and it goes down to 10% loss.
You're getting the picture, that is not always a good idea to run high-current DC very far. If you're still set on doing this, I would suggest 4/0 welding cable, you should get be able to get the voltage drop down to 5%.
Anderson Powerpoles are good connectors, but I don't know if they make them big enough for welding cable. You don't want the connector to be the weak link.