from looking on google maps the road although very narrow doesn't seem to be a problem at all for getting down their lane, however if its an issue then you are best phoning the owners and asking them rather than relying on hearsay
I checked on street view, which the satellite version of google maps went to when I zoomed in. The main road looks single track with grass growing down the middle & mature overhanging trees. Can't see a gate as such, but it looks like you need to approach from one direction as the gravel drive goes off the Tarmac road at an angle that would be difficult in the opposite direction.
The website mentions this long winding drive, and has a video with some huge caravans pitched up, so you shouldn't have a problem. They'd advise when you booked.
Looks very pretty! But has chickens, which would drive my dog demented.....
The drive down the lane and in through the gate is worth it. We spent a few nights there a couple of years ago and the views from the CL are lovely. Every pitch is fairly private with short grass but the parts between pitches are left long for the wildlife. We were sat out one day when a little mouse/vole shot out from the long grass pursued by a weasel/stoat. The mouse/vole was no match for the weasel/stoat for speed and it was soon captured and dragged into the long grass. There are also wildfowl weandering around which we fed regularly. A lovely site.