I don't allow my Yorkie's to roam the house at night. My yorkshire terrier's are confined to my bedroom and have learned to sleep the whole night through on my bed with me (they don't wake up until I wake up). I think it is much better for their "potty schedule". If you don't want your Yorkshire terrier being on your bed or in a crate, maybe you could make a little x-pen in your bedroom. I just think it could be dangerous having your little guy roam around at night. There is no telling what he could get himself into unsupervised. Having him confined somewhere might eventually teach him "this is bed time" and to rest at this time... but giving him access to roam might make his sleeping habits a little funny. Also, I think there are potential dangers with your Yorkshire terrier sleeping with a leash on, like accidental chocking maybe?
Good Luck with finding an answer!! Your Bentley is such a cute lil guy
Also, increasing the amount of exercise he gets during the day might help with his inability to sit still at night time.
I'm sorry! I know that is not the best advice ever. Hopefully another member with more experience with this problem could chime in with more hopeful advice then I can give lol.