I am the same make the most of the day there's always tomorrow for the next one
Not necessarily - I've done a lot this year and I wouldn't have done half as much without joining visits because I was in the area. For example:
Bristol and Slimbridge
Blackpool and SeaLife
Crocodiles of the World, Cotswold Wildlife Park and Cotswold Falconry
Lotherton Hall, Harewood House and Tropical World
RSCC and Wingham
All of these bar the last one were day trips - I probably wouldn't have gone so far just for Slimbridge, and Bristol isn't huge. So, if you see everything there is to see and there's still time in the day, why not add something else