Keep it simple this time of year!
You have not mentioned what type of heli you are bringing back.
I would take the coast route. (Carry life jacket if possible + raft!). As you will have to transit Nice airspace over the sea at or below 500ft amsl.
Route into either Nice (No avgas) or Cannes.
If weather permits and Nice air traffic, then plan to go to Lyon Bron, Troyes, Le Touquet then home. Nice and simple with enough spare fuel for diversion planning.
Unless you have the experience (then of course you would not be asking!) avoid the mountains.
Fly safe!!
Forgot to mention.
Charts I tend to use the Jepp 1/4 mill for the whole route. Handy as they have the Lat/Long of the vrp,s on them. Order them for Jepp of there web site or from the UK office 0044 1293 842454.
