I've just put in some large polyethylene containers for feed and water. I too am sick of refilling every day and trudging back and forth carrying stuff. The black container holds a whole 20kg sack of pellets and the water container is 50 litres. I just bought cup and feeder kits on Amazon and installed them.
I figure if we get a hard freeze this winter (last year we had -15°C and a lot of snow), then I'll insulate with bubble wrap and it's in a sheltered spot rather than exposed so that should be fine. Chucking hot water over the cup valves might be needed.
I didn't put in a drain as I never envisaged emptying and cleaning it out very often, given that it has a tight lid and it won't get contaminated by dirty beaks due to the cup valves. Well that's the theory, we shall see. Its only been there a few days so far.
I like your ingenuity, OP. But it looks like a lot of effort and wood sawing!
I made two feeders and two waterers and it cost me £66 in total. I did have one container already that I repurposed from being a storage feed bin.
Happy to send links if anyone wants, though it's for UK Amazon.