For copper you can build a work bench and put walls and a roof around it and keep repairing your antler pick axe until the copper deposit is mined out and then load the ore in a cart and take it back to your smelter in your Meadows base (bonus points if your meadows base is on a coast).

Once you have enough bronze for nails you can build a Karve and sail around the coast of black forests looking for tin and load ore from deposits of copper near the coast onto the Karve and sail it where you want it.

Returns all materials used.

All are returned.

The only time you don't get all your mats back is from Campfires and Torches/Sconces.
If you have a main base you can portal back to you only need to carry the mats to build a portal. You can find wood/stone to make a workbench and campfire almost anywhere. If you're more nomadic I'd suggest building a cart to carry stuff in. You really don't need much... 5 Surtling cores for a Charcoal kiln OR Smelter. Everything else you'll need you can find on your journey. Maybe carry two iron ingots if you have them. Then you can build a Stone Cutter. I often find halfway decent Stone Towers I can refurbish in the Black Forest and use as a base for smelting copper/tin, and if you're lucky and find one with Swamp and Mountains nearby you can do Silver and Iron too!

All stuff you get back. Only exception is any wood from a campfire, resin from any torch, or the Core Wood from any built Spike Trap you place.