Using an RV to move across country with pets

  So because life likes to make it difficult to get from Florida to California with a bunch of pets (4 cats, he had two and I had two, yay brady bunch! Then we went crazy and got 3 rabbits too!) and my mother does not want them in her house but we have to live with my parents until my boyfriend finds a job so we know where we can get an apartment (I already know where I will be working) We are left in a bit of a bind. What we have worked out is that we could potentially buy a cheap used RV drive it back, then park it in my parents driveway and keep the pets in there until he finds a job. If the neighbors complain about it being unsightly or what not we can always park it down the street at a friends hidden large lot that we used to use to store our old tent trailer.
  I have found a few Old class C motor homes all with around 50,000 miles and around 1985-1995. prices around 8,000 which I could pay for with cash. But is it reasonable that an older model could make the 3,000 mile trip? Not that we have much of a choice, unless we wanted to buy an SUV and tent our way across but then we have the same problem of not being able to keep the animals at the parents. Do the older ones have the similar 5-10 mpg or are they worse? I did do a lot of research on what to inspect (propane, brakes, water waste valves, converters, etc) but anything really important you all think I should know would be great. We love our animals and they are a part of our family, and we are completely unwilling to give them up.

Oh and really all it needs to do is get us from point a to point b, be able to house the animals for a couple months until we get an apartment and then hopefully we can sell it and buy a used car.

4 cats and 3 rabbits in a class C. The odor would knock you out.

We are pretty much immune to the odor as it is, 4 cats, 3 rabbits in a small apartment

Unless planning to keep it might be hard to re-sell  ~~  most folk a 'funnier' about smells than visual condition.  JM2?

I guess it's doable. Do you have another vehicle that you need to take along or is the RV going to be it? Do you have to sell the RV when you get to California or could you keep it? Are your parents ok with this whole plan? 5-10 MPG is pretty much it for a gasser motorhome.

Wendy

We'd probably get it professionally cleaned after, and knock the price down to around 5,000. (which is really all we'll need to get a used car) Planning to sell my car, so not taking it a long. Really would rather sell it, worse comes to worse we could potentially keep it. My parents are fine with the plan. Talking over details with them right now (like how long we can live with them, etc)