My wife visited Cornell Astronomy & Space Sciences with me in 2012. They were originally going to have me stay with another graduate student and I asked them if my wife could visit with me (as she would have an equal vote as me as to where we move to) and said that we would prefer to make our own accommodation arrangements instead of overcrowding a grad student's place.
It worked out for us that we lived within driving distance and my wife had employee benefits that gave us greatly discounted hotel rates. So, I said that since driving would save the school a lot of money compared to the students that were flying in, I asked if we could get reimbursed for the hotel instead. I asked what the maximum amount Cornell was willing to reimburse and that we would see if we could afford to stay at a hotel within that budget.
They were very accommodating and understanding to our request. They gave us a maximum of $500, which was more than enough to cover the mileage and 3 nights at a hotel with my wife's employee discount. They covered food expenses for me, including meals during the drive, but not for my wife, of course. The school also invited my wife to join in as many events with me and the other graduate students as she would like. So, she was invited to the social events and even the meals that the department provided. They even made sure she had something to do while I was in my one-on-one meetings with various professors--they gave her a campus map and set up a small desk for her to work, check email, etc.
I'm not saying that all schools will be this receptive to a guest, but I think it is a reasonable thing to ask about. For the hotel issue, I think the best thing is to explain your preference, and ask how much they are willing to pay for, and be open to having to pay some of the extra costs yourself. I think it's completely fair to request to stay in a hotel instead of with a student, as long as you don't end up costing them (too much) more than the other visiting students.
I'd be interested in hearing how it works out for you, please update us if you are wiling to