hello
@Jellywelly
welcome to TP
it's lovely that you are so concerned for your granddad and want to help
I do agree with Grannie G that the best help you can give right now is to support your nan in her decisions, even though you have some concerns about what is happening
it may be that your nan is following advice to let your granddad settle; it may be that she is so distraught and even exhausted by what has been and is happening that she needs time to look after her own health and welfare so she feels able to visit
she will be grieving for the life she expected to be living with the man she married and grieving for the loss of that man and finding her own way to cope with the emergence of the man your granddad now is - and be so very sad that she cannot be the one to look after him at home anymore - she may even feel guilty about not being able to have him home even though it's no fault of hers; it's the sad result of the dementia
it may sound to you that moving your granddad to be near you is a possible way of helping him - you say, though, that you are 3 hours away which would make visiting for your nan very difficult (she may not be visiting today but she will when it's right for her) - and another move so soon isn't really advisable for your granddad's welfare - so you can see why she wouldn't want to be discussing that when all this is so raw
she has kept you informed, maybe not as much as you'd like but she is in touch with you - so accept that for now and let her know that you understand how tough it is for her and that you are there for her when she wants support - rather than a phone call or text, maybe send her a card or some flowers
if your nan agrees, you might call the care home each week for an update on your granddad; though don't ask to speak to him - I know phone calls only made my dad agitated as he'd no way of seeing who was talking and didn't understand what was happening