Thanks to all the warnings and laughter I was unsurprised when I got to the bottom of Bwlch y Groes.
In the end I made it up with just one walk of about 400 steps (about 3/4 of the steel barrier section). The Strava official top 100 climbs segment took me 55 minutes but I did stop for about 6 times for rests, jelly babys and water.
Have stopped at a campsite just past Bala which even has a little caravan as a Bothie for tent campers

Thanks again all for a very memorable, challenging and a lot of the time fun event.
Dave