Will deer meat work as bait at -40*F? I was planning to use in conjunction with a musky lure.

Most meat, hide or fresh bones will still have some odor at those temps. Higher placement the material will help extend its calling potential. Pieces or chunks of meat can be soaked in a heavy salt brine to help reduce the freezing and release more odor.

Any of the red muscle meats of common bait use are around 70-75% water. The remaining composition is a collection of proteins, fatty acids, etc. Things that keep water from freezing will also achieve varying degrees of success in keeping red meat from freezing.

Thanks for the help!