The first issue you will have is the children, as I sure you are aware they can get bored rather quickly, therefore you have to keep them interested. So I would advise you to ensure that you try to remain online as much as possible. This may be something you would like to get away from, but I don’t reckon your kids wI’ll think likewise. If you don’t have a
mobile router I would suggest getting one, and the 3 network is almost useless on the west coast, EE have the best coverage in rural Scotland.
Scotland in October is gorgeous, and thankfully you should miss the midges, and it gets a lot quieter. If you wish to do an organised route like the NC500 it should have quietened down considerably by October, but it can still be problematic when seeking a place to park up. Quite frankly the west coast of Scotland has so many places were you can stop you hardly have to do any planning. We were up as far as Ullapool in April and had no problems finding places to park. But there’s a great carpark in Morvich near to the campsite, Torridon is awash with places to stop over. Gairloch has a great elevated carpark uphill from the local shops. Honestly just keep driving and you will se spots just off road. There are plenty of forestry carparks also.
I would think joining this forum would be beneficial to you. As well as the thousands of pois on the location app, there are are a lot of very knowledgeable people on here who are only to willing to help.
Make sure you know were you will empty your toilet, get fresh water, and get rid of your grey water. Try not to park outside houses, don’t stay any longer than one or two nights, just be careful, considerate, and use your common sense, and you will have a great trip. Enjoy.