The plan to remove the tiles with the underlayment is probably the best approach. Disposal may be a problem.
I have no idea what the disposal would cost or where to dispose of such materials in Canada.
I did a Google search and found several links:
The common opinion of all that I have found is this;
"You should opt for the removal of asbestos floor tile only when it becomes friable i.e. the asbestos crumbles in the powdery form when it is subject to pressure by hands. However, make sure that you regularly monitor even the good and intact flooring. There is no need of removal of asbestos floor tile if the tiles are intact and in good condition."
Would I expect tiles from the 40s to have asbestos in them?
You need to contact the dept of building in your area for more information on disposal and the possibility of DIY abatement.
A good Canadian link may be this one;
There are several links at the bottom of the page and an address that may be helpful.
Good luck sir,