Giordana Roubaix Bib Tights (with windtex)?
I just got them today - and boy are they thick.
I have a 43 mile commute tomorrow in 19-20F. Will I sweat buckets under these? I will be carrying a Camelback and have roughly 2500' of climbing. I usually wear fleeced knickers, leg warmers, and when it's real cold, a pair of thin tights. I hope these new puppies will be all I need tomorrow.
Worked great. I rode to work in 18-19F for over 40 miles and didn't need anything more on my legs. I had my team bibs on of course for the padding, but beyond that I stayed comfortable without overheating.
Windproofing fabrics are definitely the key. You don't need to suit-up like the Michelin Man, and when you get a bit warm, you don't break out into a clammy sweat like you do with waterproof rain gear.
Using a non-padded bibtight is the most cost-efficient way too, since you can use all your regular summer bibs underneath then, saving you from having to put the windproof bibs through wash after wash after wash.
The next best thing would be a pair of Santini Breezewall windproof leg warmers.