[Bill]

The new tanks take the old fittings? I don't think I knew that! Someone was thinking after all - that's good news, as I have a bunch of hoses and adpaters with the old fittings.

If your TM is like mine, the regulator is a two-stage device with both stages built into one housing. In other words, there is no access to the midpoint between the stages. That means that you either come off before the regulator (full tank pressure), or after the regulator (low pressure for the appliances). If your Heater Buddy runs off the little one-pound tanks, then you want the high pressure connection.
As Aaron noted, this is NOT where your refrigerator line is hooked up - the refrig line is low pressure.  However, it is easy to put a tee in the high pressure line from one of the tanks, and run a new hose or pipe to your Heater Buddy location.  You just won't get the automatic tank-to-tank switchover, since that happens within the regulator, and hence after your tee connection.

This Heater Buddy sounds like a good deal. It would be particularly useful if you are dry camping and your battery runs down so the furnace won't run.  I noticed the other day that Home Depot has something similar, if not the same thing. Think I'll check it out.

Bill