So, it turns out there's already a nice online tool (Veloroutes) for doing what I did yesterday. Here is a link to a route similar to the one I posted, except that this one does not deliver you directly to my doorstep. I considered that to be slightly imprudent. Here is the profile produced by Veloroutes.org:
With Veloroute, you can export .kml files that are importable to Google Earth, and they already have the elevation data, so you don't have to go through the ordeal of filling in the .kml file. I still want to be able to play with the profile, so my next step is to write an Excel macro to import .kml files. More to come...
1 week ago