A full outdoor planter can weigh several hundred pounds once the soil is wet, which is more than most people can safely lift. Emptying the soil and moving the container and plant separately is almost always faster than trying to move it whole.
Pro tip: Rent or borrow a two-wheel hand truck rated for at least 300 pounds if you have several large planters; it pays for itself in one trip.
Watch out: Lifting a full outdoor planter without emptying it is one of the most common ways people injure their back during a move.