When Jill was in a care home for a year, she was whats known as an R4 ( Residential 4) R5 is for a Nursing home and the Council pick up the tab in both cases. We did have to pay £319 per month towards her care and this came from Jill's own weekly money. ie: Her State pension and Pension Credit.
If the NHS are already funding your partners needs, then surely they would continue to do so, though you may find yourself with less money as I did having to part fund Jill's care needs?
Carers UK help line will know, or the Citizens Advise.
Good luck Sundance.
Aim for the moon and if you miss you will still fall amongst the stars.