Steve Barker wrote:
You're best bet is a 10 gallon electric. You can plug it in a standard
outlet, and then feed it with the hot from the far away unit. You'll have
instant hot and it won't use much energy since it will mostly be being fed
with hot water.

Are there any code issues with feeding a second hot water heater from a
first one, as you recommend? I had heard about this configuration
before, but I thought maybe I heard wrong. The tank would have to be
under the house. There is not enough room under the sink.

The recirculator is a good idea, too. I had not heard of there being a
switch at the faucet.

Thanks to everyone for weighing in on this question. An unvented propane
hot water heater is now out of the question. The crawl space is about
three feet, but I don't think that's enough to correctly install a vent.
(Doesn't the vent have to point "uphill" so that the exhaust can escape?)