A ladybug just landed on me but its february and its -10C out and dead of winter. It may have come from my valentines day flowers maybe? It was kinda nice to see.
One might be kinda nice but 10's of thousands hibernating inside the garage/basement and getting in through duct work are a real PITA. We alternate winters between Boxelder bugs and Lady bugs (Asian Lady Beetles). Many who live on farms have similar problems.
Just be very happy you only have one!!!