To water my indoor plants, I am using a small capacity watering can. 32 floz if I remember correctly.
I understand the annoyance factor when it comes to refilling the can constantly. The way I rationalize not buying a bigger can is the ability to get into the pots and all around the plant to truely saturate the substrate. The total weight is also easy to manage.
I partial got around the constant refilling by staging three 1 gallon jugs filled with water. I refill those at the sink. It also allows me to mix up my fertilizer in a larger quantity instead of doing it for each can fill up. Yes I still have to fill the small can up, but I make less trips to a faucet and I am not spending more time measuring my fertilizer.
This is one of those "pick your posion" sort of positions.