Transportation from Llandudno to London Heathrow

The train would be your best option, in my opinion. You can look for trains on Transport for Wales, which will give you options for trains. That said, I don't think tickets for that period have been released yet. You'll probably have to wait a couple of months before you book it. But you can do a dummy booking through September if you want to check the routes and cost, etc.

I'm sure someone will pop up here with more definite information about buying Advance tickets, which are cheaper. You will probably have to take the train into London and then transfer to LHR. Regardless, I would definitely suggest leaving on the 3rd and heading to Heathrow, then getting an airport hotel there. We can give you some options for that as well, if you want. Just let us know what terminal you are flying out of (of if you don't know, which airline).

It's Avanti trains you would be travelling on- a through train from Llandudno Junction to London Euston. There is a nicely timed train at 0937 from Llandudno Junction (Connection from Llandudno at 0904), arrive Euston at 1235. Avanti weekday bookings open 12 weeks before travel.

An Advance Train Specific ticket on that train in mid September is £55 before railcard discounts.

However if you buy the ticket from Scotrail you will be offered a fare of £36.50- as they 'split the ticket' at Stafford (you stay on the train when it stops there)- £1.60 Llandudno Junction to Llandudno, £14 Llandudno Junction to Stafford, £21 Stafford to Euston.

We did that route last year, Llandudno to London Euston, with a change in Chester. As noted a “split ticket” can save a significant amount, and Scotrail is apparently the only operator that offers this. Another company that does, though, is Trainline, which is where we got ours. They are a third party reseller, but a very reputable one with reasonable commissions, and their web site is extremely user friendly for US customers who may not have as much experience with the complexities of the UK’s railway system and its ticketing structures. I think we saved about 20 pounds each on two tickets using Trainline compared to what the actual operators (Transport for Wales and Avanti) charged, Scotrail aside.