ive had first hand experience of the Brecon Beacons, in the late 80's, mostly marching all over them in the Army.... No matter what time of the year, its either wet or cold or just both....lol
Ahhh - so it was you made it so muddy there marching all over it, was it? lol
Camping with your baby is such a good idea, its good for them to take in different surroundings and experiences at a young age - fun too. Used to do this when mine was a baby and he used to love it - Have a great time - sorry no advice for fest though :)
May be a bit late now but I still think a carrier is the best option. There are loads more than the highstreet choices out there (carriers that civilisations have used for thousands of years - pushchairs and prams were invented in victorian times for nannies of well off families!) My pushchair has been in the back of the garage for 3 years now and I regularly carry a 20 month old for hours and hours (all day has been known) which feels no heavier than a bog standard rucksack, and occasionally carry my 4 yr old for up to an hour or so at a time. Do an internet search for wraps, mai tais, ssc's pods, search for a natural mama site with info about the different types and even where you can get hold of new and pre-loved! Proper carriers are comfortable, anatomically far, far better for the child and they will be happier as they can see what you can instead of peoples knees and they will fall asleep there - especially great if you wear them in a back carry!
There were loads of little ones at Greenbelt Fest last weekend. Those 3 wheelers with large wheels were a boon, small wheeled buggies just got stuck on the field. With a hood and rain cover babe will be nice and snug, and will probably enjoy all the interaction. Nothing like a responsive babe to make complete strangers start pulling faces in the hope of a grin or a giggle!
The usual considerations about keeping warm will be needed, those all in one quilty suits are great, and don't forget a hood/hat and mits for littley for the cool evenings outside. A rug to throw over the pram will also help muffle the sound and encourage sleep by keeping babe in the dark when it's time for a nap. Make sure there is adequate ventilation and babe doesn't get too hot though.
Other than that, LOADS of baby wipes, extra babygros, more nappies than you think you will need etc...
We had a FAB time! Took the big 3 wheeler pushchair and im so glad we did! A lovely couple camped next to us let us leave it in their awning over night! The weather was great, the setting was stunning and the people and atmosphere were great! Loads of children of all ages there - babies even younger than Joel! Joel - well we hardly knew we had him - he was so busy taking in all the sights and sounds and fresh air - when he wasnt zonked out from all the excitment, he was enthralled by all that was going on! We totally relaxed, everything was fine and i cant wait for next year!