My last two toy poodles were 6-9 weeks old when I bought them and we worked 11 hours per day. They would have never thought to be bad in their all plastic carrying cages. I gave them a treat and they didn't care if I left or not. They slept in them at night also and anytime we left the house. It was their safe haven, it was also a safe place for them when they were pups. I do leave a radio on a talk station when were aren't home.
I was not going to replace anything because I had a soft heart and decided to get pets.
I hope you can find a good solution.