I finished reading Omnivore's Dilemma not too long ago and it really hit me that I have not found any truly tasty free-range eggs in Toronto. I've tried all the ones available at the supermarket as well as several poultry/egg shops downtown. I've also tried the eggs from the egg vendor at the SLM north on Sat...both nothing has hit the orange and tasty yolk I expect from a TRUE free-range egg. I suspect most of the 2 week unlocked cage type as described in OD, rather than a TRUE roaming bird.
You have posed a really tough question, and it has exhausted several threads recently. The only true answer is to find a farm with free range hens, and visit them every week or two.
Most farmers keep their hens inside because of predators such as foxes, coyotes, and dogs, I know a farmer in Mt. Forest with free range hens, and wonderful eggs, but his major business is beef and pork, so it is a sideline , just like his few goats ( www.beefconnections.ca ). No farmer is willing to take the risk and provide a consistent supply of the free range eggs you want.. A small hobby farm is your best bet, but difficult to source.
My brother in Sundridge has about 100 true free range hens. In fact when customers come to buy eggs they are usually met by a bunch of hens. At night they all go into the coop until morning. He also has 6 horses and 2 llamas. The llamas protect the horses from coyotes and they see the odd one but his birds are roaming in the same general area and I'm sure they benefit from the safety. No other animals seem to bother the hens, although he also has a hen friendly dog that I'm sure keeps the smaller predators away. Right now he can't keep an egg in the storage fridge as he has enough regular customers that make up the demand. In fact with cottagers in the area he just doesn't have enough. He limits his chicken numbers as once the fall comes and the cottagers leave the 8 dozen eggs a day he gets is just right. BTW he sells his eggs for $2.50 a dozen. I'm surprised there isn't someone selling "free range" eggs at the outside Markets.
With the chickens mentioned above they still have the means to get out but don't on really cold days. However the coop is large and heated (so the eggs or their water don't freeze) and they get fed the usual grain. To supplement their feed and to make up for the natural food they feed on in summer my Brother gets outdated fruits & vegetables fom the local supermarket and feeds it to the hens. They love tomatoes and lettuce. No one has ever complained about taste difference. Also as egg laying depends on daylight he also has a light on a timer that extends the "light" to replicate summer hours.