Take everything you have. Try to sell any equipment you are not actually going to use.
Make sure you have both teleporter stones in your inventory, then save the game. Now put a container in your inventory, open it and start piling stuff in the container. There is a bug with the weight calculation in that the weight is not updated automatically when putting things in a container in your inventory. However, if you move, pickup, drop or equip anything the weight will be re-calculated, and you may be carrying more than your maximum weight. When you are so overloaded, nothing will go in your inventory. If equipping an item was what caused the weight calculation, what it replaced will be destroyed; if trying to drop a chest somewhere where there was a red x caused it, the chest will be destroyed. However, if you save first and are careful, it is a handy way to transfer a lot of stuff.