What complaint does the father have about the place where the house is located?
In the beginning of the story, the father, Mr. White, complains the house is located on property that is too remote or far away from other habitations.
According to Mr. White, the place where the house is located is one of the worst of all the "beastly, slushy, out-of-the-world places to live in." In other words, Mr. White doesn't like living in such a remote area. He contends that, because they live so far out in the country, the landlord or city government (it isn't clear who Mr. White is referring to) doesn't care to keep the roads clear, especially during inclement weather.
As a point of contention, Mr. White complains that the "pathway's a bog, and the road's a torrent." Here, he means the paths have been inundated with rainwater. Muddy or bog-like ground is notoriously difficult to walk on or wade through. Also, it appears that, due to the storm, the roads are flooded or buried under flowing streams of water. This state of affairs partly explain why Mr. White doesn't think Sergeant-Major Morris will show up.