I do not know how to close this thread.
Thank you everyone for your suggestions & the help.
I will need your opinion when I want to upgrade to a better bike in a few months time. Understood I need a budget gravel bike after cycling in Peak District. I also realised I like climbing rather than biking on flat surfaces.
I will also probably ask for opinions on how best to get ready for this event. The event company did mention they will send a training schedule but I just want to climb hills and not worry much about anything else. Do a few long endurance rides (twice monthly from January) and build some leg strength.
Also, signed up for the Dragon Ride 300 km challenge. Keeps me motivated whether I do it or not. No idea how I will raise the money for charity but yeah, I will give it a good try. Wish me luck.
Entries are open if anyone is interested in slaying the Welsh dragon. Wish you luck if you are in.