When going out in inclement weather conditions - wet, cold etc., I have personally found that having the lens in a dry bag is a good solution. These are designed for hiking or kayaking and thus meant to protect gear in extremes. To give you and idea of the principle - usually they are a sealed bag, the opening of which is sealed with a roll-down neck that is then tied. This may be too bulky for you.
The 7 Best Dry Bags of 2024 | Tested & Rated
What I might often use is a holster or lens case with a zip-lock bag inside. Your greatest risk is when you want to open things up to change lenses. In my own situation, I never change lenses in the field and I have a body for each lens that I will use - but that is not for everyone, given the cost, bulk and weight.
Definitely, going inside with a camera that has been exposed to really cold conditions, it is wise to have the whole camera inside a sealed zip-lock or similar bag to allow it to warm up and not let condensation from the atmosphere condense on the cold surfaces of the camera gear. When it is really cold outside there is minimal moisture in the air, so sealing the camera with its dry atmosphere in the zip-lock bag allows the temps to increase to room while not adding the humidity of the warmer atmosphere.
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
