I added heated seat (Russel Day long) and heated grips ("Hot Grip brand) over the last year. Otherwise normal street clothes as base layer (today my regular Tilly Travel Dress socks, jeans, t-shirt and normal shirt. Over that "Warm n Safe" brand heated jacket with an Aerostich wind blocker fleece soft shell over that.(I halve another soft shell that I add when it is further below freezing.) Over my jeans a pair of Aerostich wind blocker fleece pants. "Warm N Safe" heated socks over my regular socks (this came with age. 10 years ago my regular socks were enough down to -10 for short hour long rides.)
Over the above my Roadcrafter R3 one piece (which I wear all year round) that provide absolutely no inflation but does a great job of stopping wind and rain. Warm n Safe heated gloves. I have 4 variable controller. Seat and grips hard wired, also gloves and socks sharing one remote control circuit and jacket the other remote controller circuit.
Realize it's taken me over 10 years (and over 550,000 km) to find out what works for me. Much of it is expensive but since I often ride over 50,000 km a year for me it's less expensive than the gear that costs less and lasts less. (My 2015 V-Strom DL100 0 that I bought end of July 2015 turned over 216,000 km today.)
..Tom