Did I really just type that as a post title? Could it be I'm sitting home in a flippin deep freeze snow storm for 2 days starting to go stir crazy?
Anyway, I think this size would be perfect for us (info taken from Colorado Yurt Co's website).
27' Diameter Yurt - 572 square feet and 12'3" tall in the center (13'2" with taller wall option). This is the "tweener" yurt for when a 24' yurt is too small and a 30' yurt is too big. Can be transported in a heavy duty truck and a trailer or split into two loads with a heavy duty pickup truck that has racks. Five people could erect this yurt in a weekend if they study the set up instructions prior to the installation.
572 square feet with lots of outdoor living space should be more than adequate for a part-time home a couple of months out of each year.