[GoinAllTheWay]

6 of one, half a dozen of the other IMO. Both cases have pros and cons although pretty minor I'd wager.

1 large idle tank is going to lose less heat than 2 smaller ones, that's really the only "bigger" difference I can think of.

As for the right now, you have plumbing in place for 2 tanks. Moving to one is likely going to require a bit more work so bigger bill.

**edit**

Here's another thought, you could possibly have some redundancy with a 2 tank system. If one dies, you could possibly rely on the other, depending on how your plumbing is set up. Handy as it sounds as though you are remote and help may not be as quick to arrive compared to living in the city.