MamaG... Please try not to worry. If they are saying that the placenta is touching the os ('os' is Latin for 'mouth' and it's the medical term for the opening of the cervix ... at the uterus end rather than at the vagina end, iyswim) rather than covering it at 24 weeks, then there is every chance that it will move before your next scan.
The placenta doesn't actually 'move'- it stays attached in the same place, but your uterus expands and so the position of the placenta relative to the os changes. The best way this was explained to me was to think about sticking a piece of sellotape onto a balloon near to the opening. As you blow up the balloon (= as your uterus expands) the sellotape (= placenta) appears to move further away from the opening. It's only if the sellotape was stuck actually over the opening that its position wouldn't change as the balloon was blown up.
If you are worried (which you obviously are... sorry, that was a stupid thing to say), you could ask at your next appointment (or even just phone the hospital and ask) what grade of placenta praevia you have. As lulumama has explained, grades 1 and 2 are almost certain to be OK and even grade 3 is often OK in the end.
You could also ask if you could be re-scanned at 34 weeks rather than 32 to give your placenta maximum time to get its act together. My placenta was just touching the os at 20 weeks with dd2 but I was scanned again at 34 weeks and it was fine and I had a wonderful VBAC.
Having said all that (and I really don't want to freak you out now, but it's best to have the facts), if your placenta hasn't moved by 34 weeks or thereabouts and given that you are an hour away from the hospital, my experience suggests that you probably would be safer in hospital. My experience was quite extreme (grade 4 placenta praevia -with a placenta described as 'hanging by a thread' - and bleeding from 27 weeks onwards), but my hospital wouldn't let me go home (from 27 weeks till dd was delivered at 36 weeks!) even though I only lived 10 minutes from the hospital. They said that, if my placenta did 'go' (including if I had gone into labour spontaneously - which is what they'd be worried about in your case from 37 weeks onwards) I would have had to have had my baby within 10 minutes (c-section under general anaesthetic) in order to save both my life and the baby's. An hour - even in an ambulance with blues and twos and everything going - would be way too long. It is very very rare, but if it does happen it's very serious indeed.
Likewise, if you do have any bleeding at all, do go and get it checked out asap, just in case.
The two weeks in hospital would be a PITA, but if you think that they could save your life they are worth it. (This is how I think of the three months I 'lost' during my pregnancy with dd1!) Knowing now that this might happen, gives you time to line up someone to come and stay and be with your other children if necessary and so on and so forth (even though it'll probably be unnecessary).
Having said that (and please don't think I'm trying to scare you), I think it's extremely likely that everything will be fine and that your next scan will give you the all-clear. Sorry this is so long. (Subject close to my heart!) Good luck!