What happens when the SM goes on vacation?

I wrote this message months ago in the Scrum Practitioners linkedin group and i got a tons of good suggestions, you can read in the discussion https://www.linkedin.com/groups/52030/52030-603948094888458650
I was organizing the vacation using a scrum/lean approach

Let me see if I can write it shortly how we did it with an iterative approach.

We started discussing about this vacation 8 months ago and had immediately focus on one main subject: the nature of Australia.
Like usual we begin collecting info, ideas and immediately recognize it is a big trip that need a certain grade of preparation.
We could have tried with todo-list but I thought there are too many things and a better framework could help better, so why not scrum?
Defining the boundaries of the framework was the hardest thing, sprint length, DoD are adapted a bit. But I decided to start anyway even if I was not really sure about some details. And we could "work" just during weekends :-)
I started writing some epic user-stories with the goal to determine the various area and the right time.
After some iteration we decide to travel the tropical area, the Northern Territory for example, the red centre and the grand barrier reef and a deadline: "the dry season". This was a first phase with sprints around 1 month length and the main goal was producing a backlog (remember we could do it just during weekends so 1 month is in fact just few days).
After that the second phase was with shorter sprints and smaller user story but again the focus was mainly to determine what to do according to some strict acceptance criteria like internal flights schedule, costs...

...That second phase produced a draft plan with a schedule and costs... We made reviews and create other sub-user stories, as result we finally reserved our holidays.
The third phase produced some real "shippable products" we booked the main flights and reserved 4WD cars where necessary.
The 4th phase was dedicated to define all small details and to adapt some plans, reserve hotels, fix impediments: one misunderstanding about a rent car. For 4WD you have to reserve months before. I had to find an alternative just in few weeks before, I was lucky and solved the problem it in few hours.
In each different phase the effort was different and at the last we had small userstories and just tasks.
I also modified the board at the end of phase 3.
At the end I didn't respect some scrum values at all, some sprints were not producing a shippable results. What was really useful is the iterative approach, the backlog refinement epics --> user stories --> tasks and the reviews.
Also with just two persons playing all roles it's confusing.
But it's an interesting exercise to think out of the box.