I don't mean this to be an advert, but I'm booking our travel for our May 2026 3-week trip to Scotland, and I'm running into the same issue I always seem to run into. We've flown IcelandAir the last three times we've visited Ireland or Scotland, but it has some drawbacks. I've also watched the fares over the 11 months after I book, and they never go down, so I'm pressing the button in the next day or so.
I need to have extra legroom (tall, bad knees, back problems), so we either need to fly something better than Economy or Economy where you can buy extra legroom at booking.
It's preferable to arrive in GLA early enough to get to the first stop (in this case, the train to Dundee), although spending the night in Glasgow and catching a morning train isn't a show stopper.
We flew British Air a few years ago (heart stopping Business Class fare of 8K - now 14K). That fare is just contrary to my Scottish blood, no matter if we can afford it. BA now has Premium Economy at a fairly reasonable price (4K), but due to our feeder from MFR, we don't get to Glasgow until 5pm. IcelandAir, on the other hand, has a two hour shorter longhaul (SEA/KEF), crappy cabin service, but you can reserve legroom seats at booking, and it arrives in GLA at 1:30pm, plenty of time to get to Dundee that day. The IcelandAir fare ends up at $2500. All the fares are for two.
I've searched with KLM, AerLingus, United, American, and the timetables stink or the price is absurd.
Am I missing something?