I purchase 1/4" polyester rope for light general purpose use around the house and for camping. The rope usually comes in 100' rolls and I cut into 4 x 25' lengths. This works very well for my needs and I can always tie 2 lengths together if needed, which is not often.

Since you has so much rope, you can probably make a few 50' lengths and whatever size else that you might think you will need.

BTW, for canoe tie-down on my truck, I have always used 1"x 20' cam buckle straps (not ratchet straps). Simple, effective and is a lot less hassle then rope and doing knots, especially with cold hands.