Thanks, EP
  Seals and better insulation started on day one, along with window replacements, insulated window 'quilts' that cover the glass at night, redirecting dryer exhaust INTO the basement in the wintertime, and other mods.

  I don't think it's one OR the other.. I see it as akin to money.. you have to make what you can, and also limit your expenses, save.  I hear the advice of economizing first, then adding generative capacity, but I am always looking at both sides of the equation.  I also hear how people have added a little generation, and it has further inspired them to take measures necessary to see that none of it is ever thrown away again.  I think it's actually sometimes the reverse of the common wisdom of waiting till later to get some generation/heating started.. just like I decided the adage about NYC being 'a nice place to visit, but you wouldn't want to live there' was also backwards to my experience.. I love living there, when I have a place to get home to and shut the door and chill, but I'm always more jumpy and unsettled when I'm visiting, due for the bus home, time is short and no chance to do all the things you want to do..

As far as the bike ideas above, by the way..
  I've built an outdoor Bike-Garage onto our house, so the tenants and we can access our bikes easily, without dragging them up stairs, scratching walls and doors, and fighting with them for living space.  Can't wait to expand it, and get a proper Trailer for my bike to do some errands and jobs from.

Consider a folding bike that you can easily fit into the trunk of most cars. Alternatively, a small station wagon probably will accommodate your full-size bike easily with the rear seats folded down; that was my solution for decades until I bought my Brompton folder.

Why go anywhere without a bike? My folder fits into a large suitcase and so I can check it onto a plane with no fee and no fuss. Many busses in the Twin Cities have accommodations for bikes, and I daresay other places do this on certain routes.

Carrying extra weight on an airplane to save a few gallons of fuel at the destination?  That's ironic.
"Ironic"? I think it is clever. Some carry 50 kilos of clothing; I make do with about four pounds. First things first.

Lots of people take their bikes by air. HOWEVER, that is expensive and inconvenient, because you have to partially disassemble the bike (usually) and fit it into a special and expensive carton, which is then probably thrown away and burned at point of destination. BTW, when I travel I do not take my laptop or other nonessentials. I usually take with me a few liters of good tap water (in carry-on luggage) and also a few pounds of food. This is a good allocation for when one is stranded in an airport overnight.

Once again, I question: Why go anywhere without a bike?

When it burns more petroleum than leaving it behind.
An additional fifty pounds might burn an additional quart or two of kerosene on a transatlantic run. You have any idea of how heavy those babies are? And anyway, I just lost twenty pounds and plan to lose another fifteen. Better to take a bike along than extra blubber.

I've always thought that obese people should pay more on planes.

That begs the question of how much you could save by renting something at the destination.