When we finally managed to get a respite place for Mil, we were in a similar position to you, Shettie - knowing that if she had any inkling at all that she was going to a care home, even if only for a very short stay, then there would have been huge upset.
We told Mil, only a week or so beforehand, that she was getting a free, all inclusive holiday at a nice hotel (the free part made a diference, even if it was a whopping great lie!) Depending on whether she thought day care was 'work' or a 'social club' each time we spoke to her, we told her the holiday was a 'Thank you' for all the 'help' she gave there. I didn't go on and on about it, but if the subject came up in advance, I treated it as though she was really going away on her hols, bought her new toiletries and some new clothes - and when she would insist that she didn't 'fancy it' I would 'remind' her that she had agreed to go and all the arrangements had been made, that people had gone to a lot of trouble and that if she wanted to change it after so much effort from others, she would have to 'sort it herself'. We kept it very upbeat, and always as though it was a 'done deal' and she couldn't pull out, always really positive about what a nice time she would have and how nice it was for her 'work' and helpfulness to be rewarded. . And I told the care home about what we had said to Mil, and they agreed to back us up.
So, basically, if you can, invent a reason to convince her to go - its a holiday, its doctors orders, its while work is being done on her house - and get the care home on board, so that when the assessment happens, they can back up the reasons you have given - most will, they have experience of dementia and understand that sometimes, you have to fib. And remember, its in her best interests to go, because the more chance you have to recharge and rest, the greater the chance that you can continue giving her support - without that break, you couldn't possible keep on coping and that would be worst for her in the long run.
As for visiting - we made (after much discussion) the decision NOT to visit. Lots of reasons - firstly, we felt it might unsettle her and not only would that upset her, and us, but it also might make things harder for the care staff. Secondly, it might cause her to question the holiday idea - I mean, how many people go on holiday, then have folks from 'home' visit them in their hotel? And thirdly, we simply needed a break, a proper break - and visits and phone calls would stop it being a complete break, as we knew it would be difficult to mange either without some upset and probably guilt.
It was hard, waving her off (we arranged for her to go directly from DC, as the home that it is held in is a 'sister' home to where she went for respite), but it is something you can and do get used to - keeping it in your head that its for the long term benefit of BOTH of you helps you come to terms with it.
Good luck - and enjoy your break xxxx
