That works great! Kind of a poor mans set of snow shoes. Be mindful of what will happen if the wheel spins, and the board travels up over the top of the wheel. Be sure that it won't take out a brake line, or something else that is important. Ideally, you want to drive over the board, stop, and re-set the board/chain, and drive over it again. That isn't always what happens, though.you can also take a couple 2ft long pieces of 4x4 chain them to the back of the front tires going through the hole in the wheel then put the truck in reverse back up slowly .after it has climbed out of the holes repeat as needed but that can get you out to
I have used a piece of chain in a very simple way: Take a short chunk of chain, and pass it through the slot in the wheel, across the tread, and bolt the free ends together... loosely.... It makes a simple set of "chains" and gives a little extra grab each revolution of the spinning wheel. You only need a couple of short chunks of chain, and a couple of bolts and washers... easy stuff to keep in your emergency kit. In the case of your truck, a little extra traction on the front wheels would probably be all that is necessary to make the difference.
You aren't dragging your belly, so it won't take much to get out of that mess.
One of the more experienced mud bogger/snow drivers might be able to just finagle her out as she is.
-Chuck