Hey, I'm always up for a mid-winter Maine ride (did it this past winter). Aside from cooling vests for summer, my personal thing is a small spray bottle filled with water. I give myself a spritz when I need it.
I say go for it and get another trike. Just carry a cooler with lots of cold bottles of water and take plenty of breaks. Or become a night owl and only venture out at night on trike.
I love riding through middle of night. Just me, the coyotes (in NYC it's Coyote Ugly's) and some energy drinks.