This has its limitations. Last week I was staying at Carrog on the Llangollen Railway and took a day out with an all-day rover for £15 (Seniors price) which was quite acceptable. On the Saturday my wife drove into Llangollen early and I said I would follow by public transport later in the morning. I found that, due to it being a Thomas The Tank Engine day, I could not book a single ticket and the only thing available was an all-day ticket priced at £16 even though I only wanted to take a single journey. Furthermore, if any local people were used to travel between Llangollen and Corwen - a reasonably large village/ small town - it was tough because services were terminating at Carrog for the Thomas festivities which also took place on FOUR consecutive days this week.
Fortunately there is a reasonable (for a remote area) bus service which parallels the line and I used this, but it reinforced the fact that local people should never rely on a preserved railway for normal travelling needs - not only is it very unlikely to run at all in winter, and weekday services generally only operate in school holidays, but your requirements will come a very poor second when event days are planned. This is only to be expected, since in practice local people will only produce a small fraction of the revenue required to run the operation.