How to temporarily disable iCloud photo syncing?

Use case: when travelling (especially in remote areas) access to wifi is often very restricted / expensive and every Mb is precious. I travel with my iPad and want to be able to upload photos from my camera to the device but turn off auto-syncing via iCloud until I’ve got a decent / affordable connection.

Problem: at the moment my only option seems to be to turn off iCloud syncing altogether, which then removes existing pics from my iPad - not at all what I want.

Any better ideas out there?