anyone have any tricks? It get very cold were I am, -50 sometimes...every oil/paste base I have tried seems to quit at -20 or so...tried vaseline, peanut oil, glycerin...sardines in soybean oil and noting seems to keep smelling when its cold

Some ideas...
A few guys have been playing with BLACK colored lures to utilizes the sun rays to heat up the lure and get the skunk odors active.
Lot of old timers claim that peanut oil will allow a lure to stay active in cold weather...I see you know about that...stick with it and experiment a bit
Chunks of bait that the birds can get to might create enough of a mess on the bottom of the tree to "call" marten to your trap site.

-20 to -50 temps are brutal not sure any lure can operate up to full potential in those extremes??
Be careful

M a r t E n : Marten

Martin is a bird.
Ie : Purple Martin

Even in French Canada it is : m a t r e

Super Lube Grease don’t freeze until -45. I use it as a base in my call lure, never had it crust over.

I have to override my spellcheck to spell it correctly. It will time and time again correct my spelling even when it's right.