I wear my heated winter gloves for anything below 55 or wet. No heated grips on my bike yet.
My KTM has heated grips and heated seats. I have a full heated liner - jacket, leggings, socks, and gloves.
I rode from Tallahassee to Manassas, VA, once, in December. It was mid-30s in Tallahassee when I left, and about 40 when I got to Manassas. It peaked around 55, mid-afternoon, around Florence, SC.
13 hour ride. 850 miles. Only stopped twice, IIRC. (I love my 8 gallon tank).
Was comfy the whole way. Electric undergarments and at least heated grips are the only way to roll.