Global warming
(My policy on spoilers here is that I assume everyone reading has read the novel and/or seen the 1994 miniseries, so I only cover up things that are unique to this new miniseries. With that said, this particular spoiler is so mild that I don't think it will ruin anything for anyone.)
I guess global warming is here. Just before Stu et al depart on the long walk west, Fran asks him how long it will take. He muses that they've got 800 to 900 miles to cover and might do 25 to 30 miles per day. So we can figure it will be about a month, give or take a week.
Stu then says they should get there around the end of February. So they're probably leaving in late January. Yet the massive snows that played an important part in King's novel (and also in The Shining) are nowhere to be seen. We do see some snow at various times in the episode, but never more than patches of it which are maybe 1/2" deep.
So I guess climate change is real in this setting. Or more likely, just sloppy writing. Either way, weird.