Problem with that is that it eventually runs out and you have to go back an get more. I would try to find a cave system where water falls and lava flows are relatively close by. Block them both off and dig the trench between them, with rebuildable and survivable cobblestone canal "locks" between them. That way it's a constantly replenishing source of both resources that can be controlled while mixing. Build a mining station around that area as a secondary base from your primary. Keep in mind that mixing lava and water does not guarantee obsidian (at least in my experience). I was struggling for hours with it and I was only able to harvest one block out of hundreds of cobblestones that were generated with that process. Must be a probabilities thing in the game, like lightning fires, rain and wolves like others have talked about here. I get tons of rain almost every other day and wolves run all over my world. Just the way the biome rolls, I guess.