Shorts and t-shirts tennis shoe will be fine unless you play in the snow you need something warmer
If you do the play in snow gloves are the best item
My family had on t-shirts and jeans and were a little warm... it was a suprise!
If you are just riding the tubes, You can actually wear shorts and flip flops. You will never get wet at all. But if you want to do the snow play area, you would need snickers and pants. Maybe a shirt with a long sleeve. But I wouldn't think as extreme as a coat.
We wore shorts and tennis shoes. Its roughly 72° inside.
Thanks! Your answer is awaiting moderation.