After checking and diagnosing every component of the cold start circuit and adjoining components, I reluctantly replaced my coil with a spare and ...VIOLA! 100% super easy starting in zero degree temps.
Just goes to show that these coils do indeed go bad...not necessarily all at once. Again, the symptoms were no starting in cold temps, absolutley fine in warm/hot.
Many thanks to Porkface....I was stubbornly reluctant to check the coil, as they "never give trouble". BTW, there was very little help offered (one post, in fact) on the subject.