Just to get the facts, not debate politics: do you have a source for the claim that the Prius and other hybrid and batter electric vehicles produce more carbon over their whole lifecycle?
Here's a recent report from the Union of Concerned Scientists: Life Cycle Electric Vehicle Emissions (2015) | Union of Concerned Scientists
Summary: "the Union of Concerned Scientists undertook a comprehensive, two-year review of the climate emissions from vehicle production, operation, and disposal. We found that battery electric cars generate half the emissions of the average comparable gasoline car, even when pollution from battery manufacturing is accounted for."
Of course, no one makes a Prius or Volt, etc. that can come close to towing a TT! So, back to topic: pulling uphill in cruise. Last month, I got nervous going 55 near the top of Willamette Pass in Oregon as I saw the tranny temp going well into the 200's. I pulled over at a viewpoint and let the engine cool a bit. No warning lights or anything, just feeling that we were pushing our 2010 Avalanche 1500 (gas) too hard. Was I too conservative? I saw a tranny temp discussion here a while back but it was outdated. Any wisdom?