I have a 4 year old and almost all her toys are in one room downstairs, we have a through-lounge so tv and sofa in the other room. Some days she is busy in the 'play room' on her own, others she wants a lot more input from me/brings toys into the main lounge room or I go where the toys are kept to play shop or whatever.
She's recently had a couple of playdates and I noticed all kids seem to be keen to nosey upstairs! I had thought when she started school I would move most of her toys to her room as it's mainly because she's been home with me (less so now at nursery in the morning) that I have it all downstairs. Mind, also cos there is tonnes of the stuff! It won't all fit in her room.
I just wondered what others do / have experienced because I am pondering, as she gets older, and parents no longer stay for playdates, will they want to be away from us and in her room? We do have another room upstairs that could be a toy room as her bedroom is not that big.. But then, maybe as she doesn't have siblings, she will want her toys downstairs so she can be near us even if she is playing alone.
Obviously I have too much time on my hands mulling this over! But I'd be interested to hear where your child spends their time, and if it's changed a lot with age.