:welcome4: Hi and welcome,
the advice already given is worth every penny, two weeks is too tight for enjoyment and safety.
Question: do you shop at Tesco's, if so you have time to save then send off for a EURO TUNNEL ticket, every tenner gets you thirty and its a quick trip and puts you right on the side of the fast road south. Summer June through to beginning Sept is when France goes on holiday so if you go south it could be crowded on route at several camp sites. But then you could use your on board systems. But remember the 100 litre on board tank will not last long with 4 of you. There's lots of tips so just keep asking or reading. Heed the warnings from others if part of the journey need more attention to security.
I know its a daft question, but did you pass your test after or before 1997?
You will need to find out what size the motor home is you will be getting as if you use toll roads it gets really expensive when you go into Class3. You can get all the way down to Spain by missing toll routes but that will add time.
Santandar ferry will be an arm and a leg unless you book really early but again will save you a lot of time. If you have not driven a large vehicle in Europe plan not to go to far too soon and keep an eye on the old speedo, the fines are on the spot and can, not always be high.
Sorry if I sound like a B.O.F but get it right and you will have a fantastic time with the kids.
Regards
Kontiki 645