I'm in a not disimilar situation. Only child looking after disabled mother 2.5hours away. I looked at the social welfare carers benefit but I work too many hours & live too far away - check the conditions. Carers leave from my employment has to be taken in lumps of a year, you cant dip in & out - so do check work conditions or could they allow you to work from home on some days? To get more home help hours you generally have to show need, support of the local doctor can be very useful. Or if one goes into hospital refuse to have them released into your care until you have more hours. Check availability of every daycare centre in the area. Definately get an emergency bell. Research the fair deal scheme & also look at the nursing homes - what catchment area are they in.
Moving my mother is not an option as her property is worth very little & I live in a rented flat. Also she is happy where she is and there is a good community spirit & she goes to 2 days daycare there.
What I've done is employ a carer/au pair for elderly myself. This is working for all parties but its not easy, its take a lot of management but it means my mother has company and somebody is on the spot.
What I will say is that you have to consider yourself and your family as well as your parents, otherwise, this might sound terrible but it is true, they will drain you of money, energy & time with even realising. Caring for others is a hard slog & to do so you need to look after yourself to ensure you can keep going.
I wish you all the best in making your decisions.