Wear your sandals and then slip out of them as soon as you enter. You're right it would be comfortable, so why not?
Wear what you want. It's a party, people won't mind your feet :)
Wear sandals and be barefoot. I was at a party at a friend's house and I was barefoot one I entered. I had to remove my sandals since I seen plenty pairs of footwear in the home by the entry-way.
Who cares what everybody else does? Do what you like and what would be most convenient for you. If sandals are easier then go ahead and wear sandals, if you want shoes, then wear shoes.