Did JOGLE in 2014, from what I saw it was easier to do it this way, as has been mentioned already ...
It will feel better finishing where there is more than a couple of seagulls to clap you across the line.
Depending on your route, South Loch Ness, Kendall and Devon seemed much more brutal coming the other way.
The wind thing is a myth
It gets warmer as you go south so you can lose some weight from your pannier if you need to.
Cornwall and Devon to start would be tough, by the time you are day 8 a hill is a hill, you're quite fit.
It will be easier to get home from LE for you
To get to JOG why not just get your local bike shop to box up your bike and then fly BRS-INV with easyJet, we did that from Luton, worked a treat. I work for easyJet, they are very bike friendly. Once you are at inverness get the bike transfer service to the hotel door in JO! They will even help you assemble your bikes for you.
I wrote a website with my complete preparation, hotels, bike service ... pretty much everything really ...
http://stuartmacdonald187.wixsite.com/jogle-2014/home
If you have 2 months i'd do some western isles, perhaps in to the lakes, then avoid the western pass through the industrial NW (its horrible) meander down the east to the peak district and then head in to Wales, do all the pretty bits of the UK.
When we set off (we only had 10 days spare) there was a 70 year old couple doing the same as you, they were doing it for their2nd time! 30/40 miles a days. If you're only doing say 50 miles a day then you can really enjoy it, sight see and you'll easily be able to eat and drink what you want at night without worrying about it.
Good luck, it's a fantastic experience. I have just completed channel to med and whilst it was good for different reasons, it wasn't as rewarding as JOGLE.
Cheers