Off to do the PPDS this weekend and wanted to log the miles for a challenge I'm doing. I have the UK OS trail bundle map loaded so this obviously won't cover France, but if I turn it on, will it record the route i do and then place it on top of a endomondo/strava map when i try to load it back up, once home as it will still be tracking my movements, just not on the garmin map?
I use a Garmin 310 so it doesn't have a map ability at all, but my routes always get overlaid onto the maps correctly in both Garmin Connect and Strava.
The logging just records the time with your lat/lon, so its up to the applications (Garmin/Strava) to overlay that on whatever map it uses.
Yes, it will still record a track for where you've been.
I think the Edge 800 actually has a worldwide basemap installed as standard. Though this is probably not very detailed or accurate, mostly just motorways and city names. So not a lot of use for cycling.
You could install some free OpenStreetMap based maps for France if you want, they would give much more detail.