Hot water doesn't dissolve more salt than cold water, hot water dissolves salt quicker than cold water.
Think of it this way, you're on a football field and your coach gives you a football and tells you to run it to the end field. There are football players running across the field in random directions, not specifically targeting you but they will hit you if you cross their path. In one scenario the football players are running at full speed. The other scenario are the players jogging at a moderate pace.
In the scenario where they're running each football player has a higher chance of hitting you and knocking you away from the football your holding by virtue of ground coverage per player.
In this example you and the football are the Sodium and Chlorine atom ionic bonded and the football players are the water atoms running (hot) or jogging (cold).