I bought a new house with a 75 gallon tank water heater installed in 2013. Right now it's just my wife, baby, and me so we really don't need such a big tank, but during the holidays we'll have upwards of six additional people visiting. I would like to install a tankless system that I can use for most of my hot water needs and use the existing tank for bigger loads when needed. Is there a way this can be done? So far I've only come across recirculating systems or using the tank as a "buffer" between the tankless heater and the points of use as ideas for incorporating a tank with tankless. Any other suggestions? Obviously I'm trying to be efficient with this setup... Thanks!