Do we need to reserve lodging in Scotland for a trip in late September/early October or can we book it as we arrive in places for more flexibility?
Less need for those months than at peak season, but always best to pencil in reservations. The season will be coming to an end and some places will be closing up for the winter.
Tagging on to MC's post - you might not have too bad a time in Glasgow or Edinburgh , but as an example - On our last trip to Scotland , we had booked ahead for Fort William and on our day of arrival , were driving up the A82 toward town . The road is lined with B&B's and guesthouses for several miles before reaching the center of town . It was odd to see most of them displaying " no vacancy " signs at that time of year ( early to mid October ) . I realized that the signs were really saying " closed for the season " . Also , as I recall , there is a school holiday recess about that time , so even our booking ( Premier Travel Inn ) was fairly busy . Parents and children on school break .
We traveled in Scotland in late September and had no trouble in getting b&bs on the fly. We then went to England for October. As a former reply said some areas start to close for the winter season starting in October, usually after school holiday break. Check Visit Scotland Web site for more info. Most major tourist castles stay open until Xmas. The metropolitan areas will still very active with lots of cultural events etc. Friends of mine visited Family in January and found a whole house to rent on the Spey Reservoir for their reunion. Her Photos of the winter countryside were spectacular. There didn't seem to be much snow and the skies were clear. However, when we were in Scotland in September one of the reasons we drove south was that October brought the Rain to Scotland. Remember that the latitude is much further north than you might think and the days are shorter. The weather can still be mild at 50F. I would recommend is that you do your "Highlands" running around in September and your city life and near environs in October. Bon Voyage
When we went it was May and other than the first and last couple days in Edinburgh we had no reservations and no problem finding lodging.
Take the chance, take the risk. Accomodation is a finite resource. At the shoulders of the season in Autumn or in Spring, there will be fewer rivals for your money, hence more availability for you. But there will be fewer places open.
The choice is yours, but...
I know in reverse I would rather have the accomodation lined up, more time to spend on seeing things.
In most places you should be ok as there are no school holidays then, but if you are going to Skye, I would never take a chance and just turn up there, as it is popular.
I was amazed last autumn late September how busy some small places in Scotland were at the weekend, but discovered that there were various marathons/endurance events etc that Inhad not seen any publicity about that filled every room and campsite spot in town and for miles around.
The last Monday in September is a local holiday in Glasgow and the West. Schools will be off then.