Karen,
I haven't replied until now because I really didn't have any helpful information. Bottom line is...it's gonna be hard!! It would be on me, too. But I would use the boarding facility and pay for the extra playtime and inspect the facilities...make sure they won't be anywhere at all near larger dogs that an accident could happen. 
Then, I would go with my hubby and do my very best to have a good time with him. However, the entire time, I would be worried about my baby and probably cry a little along the way. BUT, there will be fun times on the trip where your mind will escape from those thoughts for just a minute or two.  
Why am I posting this? Am I just making it worse for you? I don't know...I just wanted you to know that it is absolutely normal for you to be feeling this way and I (along with a YT forum full of Yorkie parents) feel your anguish and understand what you are and will be going thru. You can do this, though! 
And, as hard as it is, just remember that when you pick your little ones up...to dogs, time is the same (I mean, to a dog, you can be gone an hour or a day or 5 days...once they see you again, it's like it was the same amount of time and they are over it and living in the happy, tail-wagging moment of your homecoming kisses) 
 
 