As opposed to all the sheep in famously temperate Australia? :)
The temperature argument doesn't stack up to me. Have you got a source?
I was also curious since there were historically Basque sheepherders in Northern Nevada, which is generally not very cool, although the mountain summer ranges are somewhat cooler.
Goat milk is relatively common, but I've not seen goat meat for quite awhile.
Lamb is available most places, but usually more expensive. Walmart carries it!
A good number of places in Texas serve goat neat, it just gets called cabrito.