Besides being too heavy for these old folks a regular 5 gallon container won't fit under our drain. Not enough clearance. We have a vegetable oil bottle we picked up at a restaurant that fits. Even that is a bit heavy. what we use most often is a large detergent bottle. Our water needs are small. Haven't felt the need to buy larger tanks with wheels, etc.
Anyway, measure your clearance, water doesn't run uphill too easily.