Bags of holding open to a pocket dimension able to hold all weight without any drawbacks. They already exist in the world, but are among the hardest items to find.
If any would be able to craft them, it would only ONLY be a powerful wizard, and the ingredients would be rediculous.
Magic Power in Layonara is supposed to be low, so if you can't live with a bag, or bags, that reduce 20-40-60-80% weight, then you are probably carrying too much weight already.