[SumAznGuy]

If you take a fixed rate mortgage, your month payments will be the same for the X number of years.
You end up paying a little more $ in the long run, but it gives you a little piece of mind as you and your wife are on your travels.

With a variable mortgage, you save some $ that you can spend on your travels, but *When* the US raises their rates, the Bank of Canada will follow suit and your variable rate may go up by 1-2%.

Ask yourself this. How much prinicple do you owe? How much of a difference will it be each month between the lower fixed rate and variable rate?
Is the difference that much that it will affect you during your travels.

For me, I think the simplest answer if fixed rate and enjoy your travel with the misses.

*** Rates have been too low for too long. It isn't that hard to imagine the US raising their rates and the BOC raising their overnight lending rates in the next year or 2. ***