In a few months I will be going on a trip for around a month. I do not know how I am going to take my cubes there. I don't want to throw them in a bag.
Why not throw them in a bag? If you wrap them in clothing or bubble wrap, and if your bag is packed enough that things aren't constantly jostling around, they'll generally make the trip pretty much unharmed.
The bags i have normally do not get filled enough. I have so many small things that my bag is not full enough. I have tried other bags but they do not work well.
I use a plastic tub and just stack them in it. I usualy only bring my mains, along with 2 non wca cubes and an extra 3x3 for tother people so they all fit in the tub. I also make sure to bring a screwdriver/lube/blindfold/stackmat timer and extra battery
Nothing will get damaged probably. You should put them in a bag on top of everything so there is not intense pressure on the cubes. My advice comes from my experience moving to Peel Apartments in Bananaland