Battery relocation- is it possible to just use "remote battery posts" in the engine bay?

Lots of great info here.
As for moving the battery to the back, there isn't weight to be saved here at all but weight distribution is a huge deal for any kind of driving. Moving a big chunk of weight from the front to the back is incredibly helpful. Many modern cars come this way including the modern Challenger. Ford cheaped-out on my Mustang but at least they put it toward the rear of the engine bay on the passenger side.

I get that you can ground to the chassis and only run a positive cable to the front...but is that chassis ground reliable? It seems like there are a lot of welds and gaps between the trunk and the engine block.

The standard wisdom is to use a 0 or 1 gauge cable, correct? It seems like all of the battery relocation kits come with 2 gauge cable. I haven't done the math but I have to imagine that this would introduce a considerable amount of resistance.