Walmart 0w30 oil ?

Is this a good idea for the winter as I have no block heater and am due an oil change?

I would like the best cold start oil at a reasonable price but would this actually be better than Mobil 1 5w30 at low temperatures?

I know that all 5w etc are not the same when it comes to very low temperature cold pour viscosity but don;t know where to find this info.

Im glad I live in cali dont have to worry about 0w oils

Any good synthetic oil will spin nicely in sub zero weather. As a test put a quart of syn and organic oil in the freezer and leave it for a few days, then try to pour it, you will see the difference right away if the freezer is cold enough.
Thats one of the reasons I use Mobil-1 oil and filters, almost instant oil pressure on ANY starts..