If the cold periods are limited, I'd leave them outdoors as long as the temp was above 28F. Then drag them indoors, even if only into the garage, while it's cold.

My lemon sounds just like the original poster's. I'm in a bit of a cooler climate and I'm keeping them in the garage so sunlight isn't that good. I have one lemon that developed in late August but it's small and not really growing. I wonder if that will make it. I only had one this year and it took 6 months to mature. I'm not sure if this is normal since this is my first Meyer but it was good. The only thing is I read that they were sweeter than real lemons. Really? I didn't think so. The size was bigger than a typical lemon but it seemed as bitter. Anyway I squeezed all the juice out of it and added about a half of a cup of water then 2 teaspoons of sugar. Now that was some good lemonaide!

From the University of Florida :
Meyer lemon

Harvest November to March

This variety's cold-hardiness make it a popular selection for dooryard plantings. It has a low-spreading growth habit with few thorns. Fruit are relatively large with high juice content, a smooth skin, and lower acid levels than other lemon varieties. Seeds: 0-10 per fruit.

Cold tolerance differs in the trees of various cultivars. Mandarin cultivars are the most cold tolerant, with the exception of Temple and Fallglo. Sweet oranges rank next in cold tolerance, closely followed by grapefruit. Lemons and limes are far less cold tolerant. In general, citrus trees are more cold tolerant after the crop has been harvested because the canopy is more compact and retains more heat during freezes.

Here is a very interesting link ----

Here is a link that might be useful: Citrus Culture In The Home Landscape