no suggestions here either except maybe bringing him into bed.
Are you sure he's warm enough? Maybe with all the freezing weather at the moment you could try an extra blanket and see if it makes a diiferance.

To get extra sleep you could maybe try something that one of my friends came up with when she was pregnant with number 3. She child-proofed a room as much as humanly possible and then put some toys in it and cat-napped across the doorway. Her boys couldn't leave the room without waking her so although the situation wasn't ideal she was getting a little bit of much needed rest.
Can you roster your DH on for a night or a few hours so you can catch up on your rest.
It's torturous when you can't get any sleep but eventually this phase will pass