If you’re planning to start with an aide (through an agency or not) for some regular hours each week, you could then work with them to cover the trip. Getting someone to do several days out of the blue is probably impossible and also frankly too risky.

Do you never go on a family vacation? What happens with your mom when you do?

Do you have a relative or close friend (or even a friend of a close friend) that could help you I worry that a short-term would be very disorienting for someone w/dementia.

I would hire someone at a flat rate for that time to spend the time with your mom. Set clear expectations for how much of the day they need to be there. 24/7 or can they run their errands as long as they are round until 10 am, between 12-2 and home by 5 for the night. Whatever works from your experience of her needs.

If the move in is midweek, I think you might have luck with a wfh 20 something and I would ask around in your neighborhood if someone’s adult child would be interested or an empty nester looking to make some additional money.