Thanks so much for the further train explanation @James! @ianandjulie thank you for the advice and kind thoughts! I had looked at Fort William on Google street view and was surprised to see how it looked in relation to how many people recommend staying there. I'll definitely check out those other two towns (or possibly even just staying in Glencoe?) since quiet and pretty scenery sounds better than a large supermarket :P I actually am not a big boat person (sadly has to do with a dizziness disorder), so it has made us re-think what we'd really do in each location. The boat trips sound great for those that can do them though! @Lola I hope we can make a visit to Oban happen, but not sure if we'll be able to with our current itinerary. That hotel is gorgeous though! If we change it around, I'll definitely be booking a room there, thank you!
So that takes me to what I think may be a final revision of our itinerary that I thought I'd share :) We sort of changed around some of our thinking in how we approach the trip and our stays in different places. We also spent a lot of time writing out realistic times for each travel leg and the time it leaves to visit each location, so I'll leave that in. So this is where we are now and I think I feel good about it. I'll post right below since it's a bit long... (apologies)
Rationale - Many people said to think of the things we want to do most and choose 3-4 main places we definitely want to hit. We love Harry Potter and are trying to fit in as many "exciting" Harry Potter places/sites as possible. And after many hours of thinking, our must-sees are Edinburgh, Isle of Skye, London, and the English Countryside (fulfilled by the Cotswolds).
So, in trying to connect them, rather than try to rush from one location to the next (since many are far away) we're trying to make the trips as much about the journey as the destination. We did a similar road trip day where we drove up the CA coast from Los Angeles to Santa Cruz (about 350 miles) and stopped numerous places along the way. Yes, we could have done it without stopping in 5-6 hours, but we took the whole day, had some great stops, and it felt like a day of sightseeing more than driving. This is the thought with the Keswick to Fort William/nearby drive, and the Fort William to Portree drive.
My other thought was that as a teen, my family moved from the east coast of the USA to California and we drove the whole country (3000 miles) in about a week - basically driving all day, late morning to dinner, stopping for lunch, and seeing a bit of the town at night. I thought it was really cool to get to see so much of the country, even if just from the car window. Plus, the fiance is excited to drive and allow us to stop when we want. For instance, we'd love to see the Lake District, and we'd need to stop somewhere, so we figure, why not at least have an evening and morning there and we can see more on a future UK trip?
Driving background (since I know it comes up a lot) - We haven't driven on the left side before, but the fiance is very excited to try (personally, I wouldn't, but I'm glad he's game!). We both grew up in rural areas of the northeastern USA, so we have some familiarity with smaller roads, but we've also lived in LA for several years, so we're also very accustomed to heavy traffic (and do know how un-enjoyable it can be - hence trying to make this more of a journey, than trudging through the drive to get to the destination).
We're fairly set on this plan, but would love to know any tips, tweaks, or feedback since you all have been so helpful so far!