For context I'm moving house and shipping most of my stuff. Shipping is expected to take 1-2 weeks. I want to know if shipping my house plants is worth considering.
I have a bunch of cacti and succulents, an Anthurium lily, a Dracena, and a Pelargonium graveolens.
With suitable preparation I don't think water will be too much of an issue, and there aren't any legal issues. I'll be moving in September so it shouldn't be too cold and hopefully won't be too hot either.
You might consider whether it is possible to ship the plants on their own faster than the bulk of your stuff. We don't know where you are, but there are certainly courier services that specialize in shipping plants around Europe.
How long plants will survive in zero light depends how actively they are growing. Plants don't just use light for photosynthesis - there are other types of photoreceptor cells which control the plant's metabolism. A dormant cactus or succulent which hasn't been watered at all for a month or two probably won't be affected at all by a week or two in the dark. A fast growing plant which is just about to start flowering is a very different situation.
For an extended period, a small amount of light may be worse than none at all, since the plant may start to make etiolated growth in the direction of whatever light is available.
I can only comment on cactus: if you don't water or feed them for a couple of weeks before they are packed and shipped there shouldn't be any problems. Pack them in white moving paper/ newsprint (without the printing).
Avoid temperature extremes if possible.
If you aren't crossing any international borders there shouldn't be any problems. If you are crossing an international border, check the CITES regulations.
It would be a good idea to ensure your plants are pathogen-free including insects, mold, bacteria, etc. Or as pathogen-free as is reasonably possible.
I have bought and sold cactus that have been boxed for a week or more many times.
I'm assuming they would die in a few days with no sunlight or any artificial light if the container is completely isolated from light since they are green plants. But you can try to conduct a simple experiment by putting a sacrificial plant into the closet or in the attic for the duration of the move that was expected beforehand.
