I never used it, but I've often thought about using a roll up plastic toboggan. Drill 3/8 - 1/2" holes a foot apart about 1 inch from the edge to allow lashing the deer to the toboggan, then drag the drag the deer.
You can also sit on it to give a moisture barrier to your butt/seat cushion. Light , durable, low-cost.
Example :. 54" x 18". ,. About $8.50 + shipping
https://www.amazon.com/Buckmans-Ski-Shops-Classic-Roll-Up/dp/B016DQL9TK#customerReviews