1. Tubing or sledding party. Take 3 or 4 kids to a ski area to tube or a cool hill for sledding. Have the kids back to your house after for lunch or dinner. You can do cake and gifts there.
2. WII Sports party. Set up a few games and a chart for about 4-8 kids and give out medals or prizes.
3. Cake Decorating Party. Go to a craft store and get all kinds of fun ingredients for cake making. (fondant and other professional items)
Copy the format of Food Network Cake Challenge. This mom told me she did it with 8 girls. They worked in pairs.
4. Take 2 friends to an indoor waterpark
5. Craft Stations Party. Have stations set up at home with 4 different crafts. Children move from station to station with a older sibling or person running each station. You can use pre-assembled crafts or create your own. Paint pictures and make cardboard frames for them. Kids can make snowflakes out of paper with different colors. Ideas are endless here!