I have been doing walks with HF holidays for a few years. I went to the Malham location early in 2025. The Malham country house is not easy to get to by public transport, you do have to arrange with them to be picked up from Skipton railway station with the others who are using public transport.
I went to their Whitby location earlier this year, and to the Church Stretton location in 2024. I found Whitby a pain to get to, though doable. Never been to Whitby before - I stayed for an extra 2 nights in an hotel in the town before my HF holiday. Whitby is a great place.
As I also use public transport to get around the UK, I have 3 of the HF locations I am particularly looking at to book next year that seem public transport friendly. Alnmouth (in Northumberland) - I was told by other guests on my last HF holiday that it was easy by public transport, tho' I've not checked these details. Bourton on the Water (Cotswolds), where I believe there is a public bus from Moreton in Marsh railway station (and the country house is close to the centre of the town). Or the new Peak District location in Buxton (but as this is new I suspect it will be very popular).
I think they have just released many dates for next year, and they seem to have some good deals.
If you are doing a week's holiday, the holiday will end Friday after breakfast. So, you would need to get their bus back to Skipton railway station and work from there to your next destination.