Hot Rod was 2 and maggie was 1 1/2. I think I had more of an issue than them. They were not happy with me leaving for work but they adapted. I would make sure that they have something to occupy their time, like toys and maybe a kong toy with a treat inside. maybe leave a radio or tv on for them to have some noise.
I would maybe try and leave for short periods of time prior to leaving for the full amount of time. For example...go outside and stay for 5 minutes and then 10 and so on. they will get used to you leaving and before you know it, will not even think anything of it.
They have no sense of time therefore, 1 hour is the same as 5 minutes to them. lol Trust me, you will get the biggest reward when you get back and get tons and tons of yorkie kisses.
Good luck to you, totally understand.