Pennzoil Ultra Platinum maybe a wait and see, the formulation might be tweaked with a bit less GTL and reshuffling the add pack to stay close to the past/current oils ability. it still is a fine oil.
I would still pick the Mobil 1 Advanced Fuel Economy 0w-30 ,its good oil for the Subaru., Lucas oil is a matter of question among the crowd here. Pennzoil Ultra Platinum is a fine alternative to mention.
In spite of the current situation, there will still be at least some oil company's that will cough up a dexos gen 3 approved oil. without up chucking a non-approved oil, mostly the popular name brands will have some.
one way to properly warm up a cvt/ engine in real cold temps, is when just started put in drive or parking brake on ,and let it sit for about a min (in gear) . or so before taking off. then drive slowly with a light foot for at least a mile.