Carhartt Men's Quilt Lined Duck Bib Overall

Are these warm enough for sub-zero temperatures?

Yes; they are specifically engineered for cold conditions, featuring a smooth, quilted lining—or in some updated versions, advanced insulation like 3M™ Thinsulate™—that retains body heat without adding unnecessary bulk.

How easy are they to get on and off over work boots?

They feature convenient ankle-to-thigh (or ankle-to-knee) leg zippers, allowing you to quickly pull them on or off even while wearing bulky work boots, which is a significant time-saver on the job.