For awhile I had a watering system running on a toilet valve. Hard water and cold temps made it unreliable. Now I'm back to a home depot bucket and horizontal nipples. My feeder is a small rubbermade trash can with trimmed 4 inch PVC elbows caulked in near the base. Every few weeks I dump in a 50 lb bag. Very little waste and it stays dry in the rain.
That's similar to me. Here in northern Minnesota, I just use the old fashion metal 3 gallon poultry fount with a metal base heater to keep the water from freezing. For my 10 chickens, I only have to refill the waterer once every 7-10 days. I use a 5 gallon bucket with PVC elbows as my hanging feeder in the coop. Works really good with little waste.
If I filled up the feeder and the waterer at the same time, I suppose I could leave my chickens for a week, except someone would have to collect the eggs. This time of year (-22F at night, 5F in the day), I am collecting eggs 3X per day so the eggs don't sit too long in the nest box and freeze and crack.
I don't have an automatic door, mainly because my chicken run is not night-time predator proof and I want to make sure my hens are locked up tight in the coop every night. I like the idea of an automatic door, but I don't think I would trust it to work every time - especially in the winter when nothing seems to work. So I am happy with a heavy wooden pop door which I open and close with a small rope.