Just noting 6 by 8 is 72 inches by 96 inches.
A fridge is:
A. Free Standing Side-by-Side
Width: 32 inches to 36.5 inches
Height: 66 inches to 70 inches
Depth without the door and handle: 28 inches to 29.5 inches
Your problem is the fridge, the door will have to open to the outside as there is not room inside, the fleshing beam anywhere but the center where you will be tripping over it to get to the fridge as you have to skin in the center or your walls will be covered in blood and gore, and you will find new ways to cuss for banging your elbows.
The advice on high ceilings is right, but that is just part as you will need a double 2 by 6 to skin off of, or your rig will eventually warp or break less lumber.
Forget doing things outside. Great dream, until you get rain, ice, snow, fog with 40 mph winds for a week.
Heat, only practical heat is propane, usually a Mr Heater, so do not gas yourself, burn yourself or singe your fur as the back corner the heater is in will be on top of you as you try to skin in a 6 by 8 foot room.
This is for an 8 x 12 fur shed. I would 2 x 4 construction or pallets for the walls. Use star screws and clamps. Put on good paper which is white for reflecting, then tin it, again with screws and pre drill the holes like a pole shed. 9 foot minimum on the ceiling and where the double 2 x 6's for the skinning rig are, or else it will be too low and your back will be screaming and as you have fur on the floor making you slip, you will cut your hands.
I would suggest looking for some used rubber roofing from a contractor for the floor. It makes cleaning things easy.
I would insulate in the future and cover with chip board as plaster board will not hold up.
If I could suggest something better, might be an old pull camper someone junked.
This is a rough white print.
