Question...how many cover up oil cooler in the cooler weather??

I run 20w50 during whole riding season (Mid March - mid Nov) so early/late in season temps can be anywhaere from 0-10C. I don't switch to 10w40..I cover the oil cooler on the GS when it gets below 12C and going to do it on the RS (with cooler) as well...just wondering what other guys do? Go to 10w40 or cover oil cooler?
When below 10C I "heat up" the oil with a small space heater in the garage before I crank the bike over...always concerned with thickened viscosity due to cold temp.high start up oil pressure ..yadda yadda...
Well, off the "Pumpkin' Fest" in Port...see the vintage bikes and car show...turn on the heated vest...ahhh