Never been to Bali. Is October a good time to go there?
Yes, it can be a good time - just beware that you’d be heading into the start of the rainy season, but you should be OK.
Highly recommend Bali - it is a fascinating place. When I went a few years ago, we took a side trip to Sumba which was super nice, too. I mention this because just a few weeks ago, there was a travel article in the New York Times recommending Sumba in lieu of Bali for travelers seeking relaxation with fewer tourist.
Lombok is also amazing and many say it is what Bali used to be before all the development. We travelled to Bali several times, but haven’t been in 10 years and surprised each time by more development.
Lombok and the Gil Islands were a highlight and if you want a splurge - The Lombok lodge is worth it with boat trip to spend the day on the Gilis.
In Ubud, highly recommend a visit to the Green School - google it.
This will be a family get together. Is there a villa type lodging to keep everyone together? We could get by with three bedrooms.