I wonder if there are limitations to the practical distance water can wick? I've been playing around with some designs, and I figured out a way to make a sip pot with a pot sitting on top of a 3.5 or 5 gallon bucket, and the wick extends down to the bottom of the bucket. The advantage is that the bucket can be filled to within an inch of its capacity, which would allow for less frequent watering... if the water can wick that distance.
My intention would be to use these in my outdoor, and dig a hole and drop the bucket in up to the overflow hole to keep the water cool and out of the sun. If it works, it would allow me to go away this summer for at least 3-5 days at a time, I would imagine. So far I have a five gallon pot over a 3.5 gallon bucket, and a 10 gallon pot over a 5 gallon bucket.
Most of the designs I've seen mass produced have low wide reservoirs, but I don't know if that's for practical reasons (like less likely to tip over, and for indoor uses less height restrictions), or if there are physics issues with the distance water will wick?