It's about 4 hours for us. Google maps generally says "I wouldn't start from here"
We went the last two years and stayed over locally. It's a good friendly show with lots of content: take a big vehicle cos you will want to take it buy whatever it is. Far better than the Welsh show IMHO because it was nothing like as crowded while still being busy enough for the stallholders to be making a living.
As I recall the discount on advance tickets was equal to the admin charge so not worth it.
Two years ago the "green energy" barn was really fully of exhibitors: last year it was about half-full so a bit disappointing. Poultry auction was good though. We liked it. If we don't go this year it'll be to avoid spending any more money.