Start with the arrival you need, then work backward
Write down your accommodation's check-in arrangements and any timed booking before choosing scenic stops. Distinguish the earliest time a room might be available from the latest arrival your host has actually agreed to accept. If late arrival needs advance notice, contact the operator rather than assuming a booking guarantees access at any hour. These are inputs to your plan, not details an itinerary template can establish for you.
Next, note the time you can genuinely leave. Loading luggage, collecting a rental car or arranging breakfast may happen before the first driving block. Put those tasks in the plan instead of treating them as invisible minutes. The gap between departure and arrival gives you a time budget. Only then choose which visits could fit within it.