The finger-cots and leaving the ML outdoors will help. Switching to 777 or real blackpowder helps too. Changing your 209 primer everyday is another helper. Just make sure the 209 primers you are replacing them with - doesn't see big temperature changes also. The main cause of hang/misfires (other than temperature changes)is having the action open with no 209 primer in place (or) having an action that doesn't seal-out the bad weather when closed against a breechplug without the 209 primer in place.

My Omega allows me to keep a 209 in place with thefiring pindoorclosed while sitting and muzzle pointing either down or up.Most MLs are unsafe for such practices with igniter in place. So if you have a moving action ... ie... bolt or plunger & keep the primer removed while hunting -- plus are using a powder other than the two I mentioned, well you are more susceptible to moisture going thru the 209 primer breechplug hole & getting powder wet faster.You-then may be better-off to buy a CO2 Discharger from places likeCabelas & it more quietly expels the load every evening. Just start fresh afterwards.

Always think Safety First!