I have an addendum to my post on this thread. After I posted my post, I had a great example of how my chains come in handy, so I wrote a few more details as food for thought.
There is room for chains. I have a B7800 with chains on all four tires and I can pretty much go anywhere. Without the chains, I've been stuck plenty of times with R-4 tires and my tractor is pretty much useless on ice and even deep snow. I either slide around or sit and spin.
I have V-bar, 2 link chains on the rear, 4 links on the front. Last year on our pretty steep, mile long driveway during an ice and snow storm, my brother got his Toyota 4 Runner sideways on one of the worst parts of the road. It was all ice and he could do nothing but hold on and slide where the road put him. It was 5:30 in the morning and he called me to come help him. I came up on my Kubota and he refused to let me hook up to his 4 Runner because not only was that ready to break free and slide down the hill, he thought my Kubota would be useless in pulling him out and I would slide down and crash. I explained I would not slide, positioned my tractor, hooked up a tow strap, and pulled him up that road.....completely ice, without spinning a wheel. My chains dug into that ice and my brother was amazed that I didn't slide down the road like he did and I had his 4 Runner hooked to me!
The one thing about my rear chains is they need to be snug or the slack WILL hit the fenders. Also, wire up the extra links that dangle at the hook up points. I use several bungee straps on each rear wheel to keep the chains snug. The chains stay in position for the most part but do have some banging from time to time. They also make for a noticeable bumpy ride. BUT.......the advantages far outweigh a little banging on the fender and a bumpy ride.