Well, you could at least try apply that reasoning here, yes. But remember that this is not real use of language—you've deliberately made it up to be problematic, so there's really no point in trying to do that, or in trying to analyse it in any way. Without any context, this exchange appears incoherent.
Linguists, especially formal syntacticians, do regularly make up examples to test claims about language. And it's easy to come up with a context for that dialogue. E.g., A might be thirsty after having been hiking for hours.
Yes, he was referring to the piece of land. Why do you think he wasn't? What do you think it refers to then, if not land?
Some people say "it" refers to "land" (without the "any"). But anyway, as an aside, I was saying Walton apparently saw Frankenstein's monster traveling on the ice, not the land, as suggesed by the following extract. All Walton could see in the surroundings at about two o'clock was plains of ice, when he and his sailors suddenly noticed the monster.
About two o'clock the mist cleared away, and we beheld, stretched out in every direction, vast and irregular plains of ice, which seemed to have no end . . . when a strange sight suddenly attracted our attention and diverted our solicitude from our own situation . . . Soon after this he inquired if I thought that the breaking up of the ice had destroyed the other sledge. I replied that I could not answer with any degree of certainty, for the ice had not broken until near midnight, and the traveller might have arrived at a place of safety before that time; but of this I could not judge.