That is a good idea. But, I need open hooks with the spring loaded catch. I have seen some of these chain kits with one of each type of hook on the end so that might be an option. I have a pair of long bolt cutters but not sure they will work on 5/16 inch chain.
However, as mentioned above, I might just try doing this with the ratchet straps I have. The problem was ratcheting them down with the ratchet handle so close to the bumper and flat down on the deck of the trailer and ratcheted to almost its minimum length. I think I'll set the straps at minimum length, drive car up closer to the front than it needs to be, attach the straps and then let the car roll back to put tension on them. That way I would not need to work the ratchet handle at all. It still might be too fiddly and if it is I'll try the chains.
Just curious, if bolt cutters won't work, how hard is it to cut this grade of chain with a hacksaw or angle grinder?