Would it be hard on my mother to move to another state at this stage in her dementia?

My Mother is 84 years old. She has dementia. It is in the Late middle stages. She also has bi-polar and anxiety. She has been living with my husband and I for almost 5 years. Recently I realized that as she continues towards the last stages that I will not be able to meet her needs. I have checked out and visited numerous Memory Care Facilities in our area and decided on the one I felt would best fill her needs. I have shared this information with my other 3 siblings. There has been talk from my husband and brothers about moving Mom to a facility in another state. This move would have a family member living near by and would be an easier location for family to be able to fly in to visit. I am against this idea and have said so. I believe that at this stage of the disease ...any move would be difficult for her. But moving her from the Pacific Northwest to possibly a Southern State I feel would not be in her best interest and would aid in her further decline. Am I thinking straight here or am I way off base?