@Peter-kinver My first advice: take a small tablet with you so you have something decent to make changes to your beforehand prepared routes in de evenings.
As regards transfering routes to your NAV, I have no experience with thz Nav 6 but there are interesting video tutorials from MRA.
Changing routes substantially while on the road does not seem like a good idea to me and should perhaps only be done in case of need (read: motorcycle repair). I would strongly recommend to research your weeklong trip and haev all the questions solved (where will I eat, where will I sleep, what will I visit, which road will I take...) before starting. Just following your front wheel withotu much planning may seem adventurous, it can also lead to serious disapointment. And in some area's (and seasons) it can be difficutl to find a place to sleep when not reserved beforehand.
Roughly explained:In my first preparations I usually start putting places to visit (starting at home and coming back to home) on a first "overview route" and let MRA calculate the route. A 5 day route may as aximum have 1500 km at this stage.
Then I cut the route in seperate routes of 300 km each that I "polish" choosing the most beautful roads (the Michelin map is a great help here) leadin to a max route lenth of 350 to 400 km.
You can of course change these distances according to the type of rider you are. For me it is very important that the trip does NOT become a race and that there is sufficient time to visit places.
Also, before embarking on a week long trip, prepare and ride a few trips starting eand ending at home. You will learn a lot