There is absolutely no getting around the 6 month wait after a successful rabies titer - don't waste your breath trying to plead with UK authorities. Seriously - this one is carved in stone. Either the dog waits 6 months outside the UK, or does the time in a UK kennel.
If you are considering bringing your dogs into UK quarantine, please - research the facilities very, very carefully.
My only experience of UK quarantine was in the pre-PETS Scheme days when it was mandatory. I toured several different facilities, and frankly was shocked at the conditions. There was no way in hell I would have left my dogs there for a day, let alone six months.
(In fact, this is why we are in Switzerland. Because of the UK quarantine at the time, my husband turned down the UK job flat. Company then asked him to consider moving somewhere, anywhere else in Europe.)
Obviously things may have changed in the intervening 11 years - after all, with alternatives to UK quarantine now allowed those facilities lost their monopoly and now have to be a tad more animal and customer friendly. However the fact remains: UK quarantine is just that - your dog will spend six months in a concrete cell, with minimal human interaction and no socialization with other dogs. (Two dogs from one family may be quarantined together, I believe - but they will not be allowed interaction with other dogs.)
I know a few dogs who had to do UK quarantine in the intervening years - and some have been traumatized by the experience.
I could not risk it with my dogs.
Were it me, I would move heaven and earth to find a temporary foster in Switzerland or in France (there are kennels in France set up for just this... give me a chance to look through my files for the info). Being separated from you will be difficult enough for your dog - you want him in a friendly facility where he will have the company of other dogs, opportunities to run and play, plenty of human interaction.
Try putting an ad here on EF for a foster, be prepared to pay the going rate - but this will certainly be more reasonable than UK quarantine. (Do be aware that if your dog stays with a foster for more than 3 months, you need to assign temporary ownership to the foster in the ANIS database, and the foster needs to do the SKN with the dog - you'll want to pay for that.)
Alternatively, could you consider commuting CH-UK for the six months, waiting to make the move until your dog is ready? My husband and I have done this - another UK stint came up when the oldie was too ill to move - OH worked in London, I stayed here with the dogs, we saw each other most weekends. Worked well.
Hoping this all works out for you and the doglets, with the least amount of stress all around.
All the best.
ETA:
When you said that the dog was not boosted in January - was that a 1,2, or 3 year vac? The UK does not require annual vacs, re-entry is allowed during the validity of the vaccination, defined according to the manufacturer's specifications. So if your dog was given a 3 year vac, you can enter the UK six months after a successful titer during the three years the vac is valid, until the expiry date on your pet passport. If given a 2 year vac, you have 2 years, if given an annual vac it is only 1 year.
Most vets in CH are giving the 3 year vac as standard. Have you checked your expiry date?
ETA 2:
http://www.cani-excel.com/pet_quaran...ternatives.asp
In France, these folks specialize in providing an alternative to UK quarantine. They can arrange pet home boarding. Kennels also available. I heard about these folks through colleagues, have not seen the facilities myself - so due diligence required.