Yesterday it started out in the upper 40's.
In addition to lightweight shorts and jersey, had arm- and full length leg-warmers, a vest and a windbreaker. Not the least bit chilly getting underway, so the same probably would be fine for 5-10 degrees cooler. Didn't need to remove the windbreaker until about an hour into the ride, and the warmers came off about an hour before the end, when it started getting into the 60s. Just about perfect.

Aside from the fact that some bib tights are weather resistant and some are extra-toasty warm, they have no real advantage over leg warmers except as a matter of convenience, and that's only if it stays cold. Same goes for long-sleeve jerseys over arm warmers. At first I thought warmers were odd, but they're really more convenient for clear days that start cold and warm up - unless you lose one.

I've also found that, when in doubt, a windbreaker is a better bet than a base layer, and unless it's going to stay in the 40's or colder, a thermal jacket can get to be too much over a good base layer and jersey. You can't stuff a thermal jacket in your pocket, shedding base layers is quite awkward, and unless it's going to stay cold, I really don't want to be stuck with thermal sleeves.