I agree that this is key and that ultimately, the hotel (via the faulty reservation system) was the root of the problem.

That said, the OP should have been wise enough to get a firm time frame for the move. The fact that she didn't IS actually her fault and by not doing so, she agreed to the default check in / check out times (and this is 11am/4pm, I believe). I find it odd that she would not press the resort on this point, since it clearly seems to be very important to her.

Now, if the resort promised her a condensed time frame for the move ('we will have you out at noon and then back in by 2', for example) and then went back on this offer, it would be a different issue. But this does not seem to have been the case.

Given all of this, I don't think the OP should expect anything else at this point. And I agree with others about the options: cancel the last night, cancel the entire reservation, seek an alternate accommodation at the resort (which seems to be available), or just go with it and enjoy the 'homeless' time.