What do you think is the most effective piece of heated gear (excluding heated grips) for you? Like if you had to start over again, what would be the order of your purchases? Start from the feet, and move up?
First thing I do typically is heated grips. On the AT I needed to commute on it before I had time to do the grips, so I installed a coax power outlet dangling below the seat on the left to plug my gear into.
For my commute I find heated jacket liner, gloves and grips to be fine. Coldest commute mornings may begin at mid 20s F, and it's an hour give or take on the freeway. It's also enough for touring, though I used to tour with just the grips--worst case my fingers would freeze a bit in the morning, which isn't as bad when you're going someplace awesome and new as when you're going to work every day.
Lower body needs for me depend on my gear and how much wind it lets through, but never needed heated anything. If I were riding all day in freezing or sub freezing weather my needs would probably be different.
I've never mounted controller to bike. Whether I've used remote or wired controller, it's always clipped to my person in a holster, and I've always done it with a single coax connection to the bike. Typically I have gloves plugged into jacket liner plugged into dual controller, and after or before mounting the bike I plug the controller into the coax outlet dangling on the left.
Mounting a remote temperature controller to the bike doesn't seem like a bad idea either, especially if you'll only use your gear on a single bike. Controller clipped to your person is simplest though. When people have issues with heated gear being awkward or complicated to use, it's often because they did wacky stuff with controller location or connection to the bike.