Two little tips I have alreday experimented

- Have always with you a pair of small plastic collars (you know, the cheap one you just have to pull on to tighten)
They will let you go back home in case you have a problem or even lose one of your rear back derailleur roller

- If you have a flat in the middle of a forest and no rubber tube to repair, you can always put grass into the tyre.
It will allow to go back home. (of course you basically need the small tools to remove the tyre from the wheel at least partially to put the grass in )

I hope you will understand what I am trying to explain in english !