I am not an attorney. However, I have spent a fair amount of time with seniors so here are a few suggestions.
First of all, the real underlying issue is related to the grieving process and the aging process. Older people view selling their home, or their parent's home, as an act of great personal loss. To cope with that loss they often simply procrastinate, allowing the property to deteriorate and lose value.
Second, as people age their ability to make sound decisions. The will left by your grandmother is going to specify how she wanted her estate handled, and by whom. That is why a caring and knowledgable attorney is of great help. It is not necessarily the legal element, but the emotional element that needs to be discussed openly.
Probate is the process of disttibuting the assets of a deceased person. Unless the will stipulates a specific timeline you may be in for a long haul. So rather focusing on the timeline, discussions with a family therapist, a pastor or rabbi, or an probate attorney wold be my suggestion.
Best of luck