Oh dear, what a fashion question!
I have three blankets for our minis. I made them each a fleece, and purchased a thinsulate blanket with velcro from Ozark Mountains, and a water proof thin sun type blanket. Some days, I put on the fleece, if it's cold and dry, and if it's going to drizzle, I layer the blankets and put on the thing sun type blanket (that works as a fly sheet too). Or, if it's really really cold, then I put on the fleece and then thinsulate blanket on top. Layering gives me more options, and our minis NEVER get wet with all those layers. Also, putting the heavier blankets on top of the fleece allows me to use the fleeces underneath that I made myself with velcro. I like the options.
I also go and put my hand under their blankets a few hours after they've had them on, to see if they are warm enough or too warm or whatever. Some days, we just take off the outer blanket and leave on the fleece if it's a really really cold day.
A few weeks ago, it got down to 37.. here in Ocala, that's frozen tundra to our horses, so we took off the thinsulate in the day, and just left the fleece on. We have a list of guidelines and what the weather and temp are. Having a written out list, really really helps keep us organized.
God Bless,
Lynn W