I think a lot will depend on the sort of friends your ds has tbh. I have had similar problems as my ds (who will be 10 this year) has a birthday at the beginning of December. You can't rely on the weather being good enough for outside activities.
The last party we had at home was when ds was 8. He had 7 friends (so 8 including him), 5 boys and 3 girls. I organised games, and then they had a party tea. The tea bit wasn't too bad, as I had done the food beforehand, and they mostly sat at the table ok.
The games I had organised very well, but it was still a bit of a challenge, as by that age many of them (esp the boys) just want to run around. At that time of year you can't always just let them loose in the garden, and although we have a 4 bed detached house, it's not big enough for that sort of activity. Which is why ds had his 9th birthday at a sports type centre.
But if you think you can cope with a home party at 9 in the winter, here are my ideas for games 
We had two home parties (when ds was 7 and 8) and the themes were lifeboats, and playmobil.
Games were stuff like -
Pass the parcel (with theme related gifts)
Things like "Dress the lifeboatman/Norman the Foreman (a Playmobil character ds has)" - you divide the children into 2 teams, each has a cut out figure dressed in underwear, and a set of paper clothes with a blob of blue tack on the back of each item. In each team the take it in turns to throw a die - if they get a 6 they can add an item of clothing to their figure, first team to dress their character wins.
Pin the whatever on the whatever - e.g. the Y class on the Severn (lifeboats) or the teeacup on Norman (playmobil), but you could do the magnifying glass on the detective etc.... So you blindfold each child in tun and they have to try to stick (with blu tack) the item in the right place.
Another idea if you are having the party in the late afternoon at that time of year, is to have fireworks, either indoor ones, you can light on a plate/tray around a table, or outdoor ones (make sure someone is available to ensure children don't get too close to them!)
Hope these ideas might help!