[LunarBerry]

I can only say with what experience I've had with my past yorkies. One died of old age, was blind the last couple of years of his life and was hand fed for the most part. The other had some complications that we thought had caught back up with her (she had some health issues when we first got her as a pup/young dog).
The last three dogs (including the past yorkies) that past away, we've actually never got around to "euthanize" when the time came, they've all past away in our homes when we least expected and suddenly. Up until near the end, they all seemed to have done fine for their situation and kept their spark right before the end. I'd say, go with what you feel is either right or instinct. In my opinion, unless they are suffering so bad that they should be put down very quickly, I'd let them live out the last of their life at home with family. I personally think they would prefer that, if possible.