I agree with you.
Through the lens of history, we can state that victory was all but assured by December, 1944, but at that time, it was not so clear.
There was great concern when the German forces began their assault against the relatively thin American lines in the Ardennes, and immediate success was achieved by the Wehrmacht and SS armor groups. Notably, Kampfgruppe Peiper’s rapid advance towards Antwerp.
Of course, we know now that it petered out, but at that time, it was not known, nor accepted widely, that it would peter out, eventually.
I believe Peiper’s advance petered out due to fuel shortage as well as determined resistance from our troops. Same story for Rommel at El Alamain. Hitler bit off more than he could chew.