I'm adding the big files by manually selecting 1/4 of it and copying to a new layer and deleting it from the current. This reduces the file size for uploading.
I'm keeping it at under 500kb as my magic number.

Let me know if it's to big to be using JOSM for.

Here's the method to the madness:

By going at it slow and steady i can:
1 - ensure the quality, and more eyes can be watching for errors
2 - i can teach others how the process goes, then more people going slowely, will get it done.
2a - the canvec.osm files would be stored on server somewhere so there always available, and no rush to get it in. Just upload around your GPS Tracks tile(s) area. Usually it's only 1 or 2 that you'd pass in a day.

3 - by working only in the area your comfortable with (and will physically travel) odds are that it will be a better map :)

4 - Once the tile 092c is loaded, i'll work on 092g12 (i think it is, that's the area that was loaded in by someone else and using geobase2osm super script.
I'll meet them in person, and do a "CanVec mapping party" this way, with more heads, we can prefect the process and then be ready to open up the can. ... canvec that is :)

Waterbody:
Any one think it's a good idea to load some big polygons to show the bay/cove/water region? (it'll show up on the garmin map) otherwise Garmin doesn't recognize the 'natural=coastline' tag, it just shows up as a thin line.
Renders in Kosmos fine though.

Personally, i'd like to add it. But it's open to the community :)

Cheers,
Sam