In a discussion on the website TheBigOutside.com, the Mira II was recently used as an example of a tent that "crosses over nicely from summer to cooler autumn use (or milder Southern winters)." Here's a link to the article

We must agree. The Mira and Gemini series tents were designed to be more than simply summer tents. They use 5,000mm water column floors, high quality fly fabrics, factory taped seams, and flies that extend close enough to the ground to keep the storm at bay. And while the amount of mosquito netting in these tents won't keep spindrift snow from finding its way in, they are structurally strong enough for many moderate winter conditions.