Last night I mined a single Black Forest boulder that was about the same size as a copper node. Including whatever stones came from the dirt embedded in it I got about 16 piles of 50ea stone. Using a Bronze lvl3 pickaxe and fending off the regular dwarf attacks I spent about 3 game days (without any stamina buffs but I did sleep thru the night). My base was a 15 second jog away. The video above showed a yield of around 7-8 piles and didn't mention it would require travelling if a portal wasn't set up where you were mining. Overall I'd say planning things out ahead of time will better determine which method works best for one's situation.