I live in Idaho which can be cold in winter and over 100F in the summer. I actually use a combination of the blanking sleeve combined with what is called a "balanced" thermostat for 195F. The blanking sleeve performs its function by closing off the bypass port to most coolant, forcing water to the radiator. The balanced t-stat counteracts the force of water flow from the pump for somewhat more accurate control of the coolant temp. The balanced T-stat is a Robershaw design often used in racing and you can pick one up from many local suppliers where it will be sold as a Prestone Premium unit in a variety of temps.
Does this work? Well, it has for years for my car, a 1968 MGB GT. Pretty much a stocker. It heats up quickly (less than 2 miles of travel, summer or winter, and maintains temp pretty darn consistently. I use a 50/50 antifreeze solution in winter and in summer plain water with a 3/4 bottle of Reline Water Wetter and half a bottle of Prestone Water pump lube to replace that lost when the antifreeze is removed. Best I can say is it works for me and has for many years. (But your results may vary! ;-) )