Good luck with your new puppy and with Toto. I read what you've written about Toto. I really don't know if this is the reason, but it could be his excessive barking at night is from CDS, a doggy Alzheimer's. My yorkie will be 17 soon, and she started barking and pacing a lot in the middle of the night several months ago. She has been on Anipryl since October, and it has helped her a great deal.
http://www.cdsindogs.com/PDF/CDSInDogs/ANIPRYL.pdf