I'll bet the OP is using synthetic or semi-synthetic oil ! I makes a big difference below 0F.
I remember almost 50 years ago, My Dad tried Mobil 1 (?) because he would visit our cabin in northern MI several times each winter. That engine spun over like it was a spring day ! It did make a few "odd" noises, but it kept running.
He gave up on the Mobil 1 because he could not stand the 3 to 5 times cost increase. He would just put a battery charger on over night or decide not to go when it was going to be below 0F !