SDoc, I think you are overthinking this a bit. You have a lot going on here, so I would say to break it down.
You transport to the ice via a road so you are going to need something with wheels at best. I would say to google images of a smitty sled with wheels. Guys have made them with removeable wheels. Once you are at the ice, you remove the wheels and have the skis to glide across the ice. The smitty sled can hold a sled on top that you can use to transport other items. Guys have designed the smitty sled to also carry the hub on the side. Once you see the images you will start to get an idea of what you want.
When you are on the ice you have a hub, so you already have the weight issue solved, these are pretty light . If you really want a floor, I would suggest using the gym mats. These are interlocking pieces usually 12"x12" or larger. They are pretty common in some home improvement stores (Home Depot, Lowes, Menards).
Or, you may want the design like you mentioned. I would suggest starting with google for images, or sketching something out and see what you want to do. What you construct it out of will have an effect on the overall weight of the system.
Good luck! Curious to see what you come up with.
Welcome to the Shanty!