Normailly I bring a laptop, external hard drives and more on vacation to process images and to back things up. On this trip I did not bring the laptop but I did bring and external SSD hard disk and an interesting device from Toshiba called the Canvio Wireless adaptor for external hard drives. This little device comes with a power supply that runs the wireless adaptor and a connected USB hard drive. There are some limitations on format for the drive but nothing complex.
When powered up and a drive connected the adaptor makes the drive available for wireless access. Toshiba has an app but I am using a app called PhotoSync so I can simply transfer my images at will to the hard drive or say from the iPhone to the drive to the iPad. This is a great way to keep my images backed up while on the road. PhotoSync does a whole lot more but for this case I am only using a portion of the apps features.
It's like having my own private cloud service without the need for internet access.