My questions relate to the following two sentences taken from the website referenced below. The goal of the lesson was to explain the uses of ということ but I'm more concerned with the choice of particles in bold.
If you go to Hokkaido in the winter, (I bet) you'll see how cold it is.
First, is the second sentence grammatical?
I thought か replaced が when it marks indirect questions? If it is grammatical, how does including both particles change the meaning?
Second, is it possible to mark an indirect question with が rather than か?
For example, is - 冬に北海道に行ってみればどんなに寒いがわかるだろう。 - grammatical?
Last, why is か used in the first sentence at all.
I was under the impression that と alone is proper and かと actually serves the purpose of reducing the certainty which is not the intention in this sentence.