Lactic Law of Gravity

Having had three sportives in as many weeks, it's now time to summarise, and turn my attention to the last phase of training before the Etape.
I have had one reasonable time - given a crash and bad weather, one excellent time, and one good time.
I feel strong and have had testing hills at the end of all three Sportives, all hills were climbed in good time.  None of them can be said to take me to the rarified atmosphere that I will b e expecting to visit at least twice on a Sunday in July
I have got used to eating and drinking - and feel I should probably be drinking more water given some of the headaches.  I also feel I am taking too many gels round with me as I always have loads left over.
I am confident in so far as I have trained over the distance of the Etape, but less confident in the fact that the sportives have barely touched the long, steep, elongated, Alpine sides in terms of elavation.
I feel that I can only train and do what is available and the local sportives and tough Surrey Hills, combines with hard fixed wheel commutes working on pace and speed is all I can manage.  
The quandry now is - do I continue with the sportives, or do I try and do hill repeats (Leith Hill repeats, Box Hill on the way home).
There are three June Sportives, Cranleigh (10 June), Goodwood (24 June and at 129 miles billed as the longest in the UK) and Reigate (July 1st - one week before the Etape).
I have a week long holiday (no bike) to ponder the next steps - but to be honest - it's probably too late.
If I am honest - I think I can finish it, but secretly - the voice inside me is telling me that to climb as far as the Col of the Iron cross will be a good effort, but a failure nonetheless.  I have printed out the map and the times and tried breaking it down, its a hell of a task to complete.
On a lighter note - when Hugo and I were over the park playing out a Newcastle United victory ina penalty shoot-out over Manchester United, we saw his pal from school - riding a bike.  This spurred Hugs on to have a go on Hollys old bike, so we are now making progress with Hugo, a great step forward given that under 16's can ride free in sportives ;).  We managed to the park and back - just another 99.9 miles left.
Lastly - the Allez needs a little care and attention, and the Langster is in an awful state - the chain covered in a thick paste of oil and grime.