Christmas this last year, I was only there for 2 nights but had like 10 days' worth of bags, wipes, barrier wipes, and scented bags. I think I only used my normal amount that I would have had I been at home.
The only thing you have to think about is how often you get any leaks. I would say for 5 days away, take a 7-day supply that would account for one leak in the week and an extra to cover any travel delays.
If you can fit one more extra on top of that in your luggage, then it will give you peace of mind, but it really isn't necessary. I find my stoma misbehaves and is more likely to leak when I'm stressed or worrying about it. Relax, enjoy the vacation, and I'm sure you won't have any problems with just taking supplies to cover 5 days.
I've only had an issue away from home once. I left my little man bag at home when going to work and needed to replace my pouch partway through the day. Fortunately for me, I work in a hospital, so I was able to scout out and find an on-duty stoma nurse who gave me a couple of everything. She even changed the bag for me, having seen I was a little flustered, and checked out my stoma health while she was at it.
The most important thing is to just enjoy your break from normality. Forget everything else. If I go anywhere further away, I would research ahead to see where I could source emergency supplies at short notice, but I doubt I would ever need to.