>> i totally agree that there should be separate areas! <<

It solves a great many problems.

>> there was a whole group of people outside on the deck in the cold--during nighttime in late november in canada <<

That sucks. Usually it's just me standing out in the rain or hiding in a quiet corner. If it's a lot of people, that is definitely a problem.

>> that honestly just points to poor planning.<<

Yep.

>> how bad does it have to be that people would rather freeze their ass off than stand inside the one giant room where the party is? <<

Typical failures include the venue being too hot or too cold, music too loud/wrong kind, or just too small for the crowd.

>> all in all i had fun though! my family got to keep the centrepiece which means i got to press the most beautiful white roses and hydrangeas. i'll likely post pictures of them once i find something creative to do with them.<<

That's good.

If you want a description of alternatives, I described how to host an introvert party, alone or as part of a larger event.