For more added weight get some old inner tubes, and make about four of them say three feet long and fill them with moist sand, and plug off the ends with wooden dowls and hose clamps. And use tie downs to hold them in place at the end of your bed where your spare is now, that will give ya easily 200 to 250 lbs of added weight, and if it's too much slide them forward, or take one off! And for added traction on ice and snow will be to have your tires cross siped! The more the tread block is broken up, the better the traction on the hwy when the roadway is wet and icy! I take my wildcat ext's off in the winter cause they break loose on ice really bad! I run a excellent tire that has a ton of siping to the tread in the winter! The pics are below to show the tread difference. By the way the all season tire does very good in the woods as well as the traction!
I carry chains only for the purpose to get out, our rule of thumb around here is go as far as you can without chains and put them on to get out, or if the conditions get worse on the way out! Chains can get you in trouble really quick!
I see you run BFG's, most people around here run them and have been know to do very good in the snow, especially on heavier rigs!