Good for you Tinks :) It was something very special for me to do and that I hope I can do again someday properly rather than bits and pieces.
It can make such a difference having people there even just to help out. One of our ladies had severely progressed MS and had little movement left in her body and great difficulty in speaking and I used to sit with her a lot and when the others were doing whatever craft or other diversional therapy we were doing that day I'd help her get involved.
Other things you could look into are charities such as Vitalise. I spent quite a bit of time volunteering with them on a residential basis and there are all sorts of possibilities there. Essentially it's for the severely disabled and their carers for a damn good holiday and some respite and we'd do all sorts. It's not palliative as such, although there are a lot of people with very serious and progressed conditions, including terminal such as Huntingtons, who go, but it's a wonderful thing to get involved with.
Not sure if they still do it but Christmas week used to be names drawn out of a hat for guests who would otherwise not have a great Christmas (alone or stuck in a home...) and they came free and we'd have one hell of a Christmas week - brilliant Christmas Day and a New Year's party on the Friday night (not that it ever was NYE) and all sorts of other great stuff - had some great Christmasses there.
There are all kinds of possibilities about if you look :)