Why don't you move some furniture down to the playroom for the party, then move it back up afterward? You could probably get a couple of the party-attending dads to help you move the furniture. Or rent a bunch of folding chairs instead of renting a tent and space heater. Or move the toys and stuff up to the living room? I wouldn't want to hang out outside in December unless it was an unseasonably warm day, and you can't really plan for that.

Party rental places will have the necessary gear. IT will not be cheap - a portable heater alone (and you might need several) is about $100 a day to rent...tents can run from the $100's to well over $1,000 for a larger model. Plus delivery and setup. But December is low season around here, so maybe there are deals to be had.

People do this for weddings, they pitch a tent outside and put in space heaters. But this is not going to be cheap.

I don't think there is something that would actually insulate people from the cold.

I'd let the kids bundle up and play outside, run some games, etc. Then eat and have cake and hot chocolate indoors followed by free play (and/or a couple more organized games) in the basement.

We live in a very tall and skinny townhome. We'd like to try to have our 5 yr olds birthday at home in December, but our inside layout doesn't work well. The playroom is on the first level with no place for adults to sit and converse. The main living area could be used, but I know my son would want everyone in the playroom since thats where the toys are.

So we have a small "backyard" - patio if you will. I could (in theory) keep the door open, giving everyone more space. However, it will be cold. Is there any sort of tent or cover I could buy or rent for the backyard space and use a space heater to keep everyone warm?

TIA!