I can leave for up to 4 1/2 days by placing my containers in big trays and pouring up to 2.5 quarts of water into the tray. If the soil has lots of aeration the plants take it fine.
I looked into Blumats but for it to work you have to convert to the system 100% of the time which is a pain in the arse. There aren’t any cheap & readily available home water systems. If I need to leave more than 4 days I would need a friend to water the plants. If it’s legal that expands the number of people you can ask to water them! House-sitter, etc.