First off welcome to the forums. Chickens generally need to be penned up at dark and let out the next morning. I suppose if you only had a few and the quarters were too confining you could get by over a weekend. I'm certainly not sure about doing that every weekend however. When younger chickens tend to gang up on others. That could be disastrous.
I would be inclined to think that an automated watering system would work well. Many greenhouses use drop hoses to each potted plant with the system set to activate by timer. They even fertilizer through the drip system which is then called fertigation.
Having electricity go off and reset a timer would be a potential downfall. With good water retaining soil and mulch the plants should go quite awhile without their usual watering cycle.
Here is an article you may find of interest concerning gardening with little irrigation.
http://www.fullbooks.com/Gardening-W...out-much1.html
If you don't mind chemical products polyacrylamides, more specifically cross linked polyacrylamides may be just what you are looking for. They absorb moisture when it is available and release it to the plant as the plant needs it for the easy version.
http://www.hydrosource.com/serv01.htm I did considerable reading on them in 1997 and am comfortable using them while organic growers would not only shy away from them but run away from them. Individual choice.
A pitfall of weekend garden or farming is cooperation of weather. If you get rainy spells, if like here, it seems they always fall on the weekend which delays outdoor projects.
Again, welcome and greetings from the land of OZ, i.e. Kansas from the Wizard of Oz movie. Windy in Kansas