Mrs. Garlic Head travels - Packing Madness

My Bach Leap 30 on the right and my Tatonka daypack on the left

Since I'll be traveling for quite a bit this summer, I thought I'd share some of my preparation for this trip and hopefully a few updates while I am on the road. (I won't be cooking much during this time). I hope you like this change of topic here.

One month before the longest and most adventurous trip of my life to date, I find myself in a state of packing madness. In the last few days I packed my backpack no less than three times. Three times.
I have always been an early packer, I like looking at my backpack standing there in my bedroom, all packed and ready to go with the toiletry bag sitting next to it, waiting for the toothbrush and a few other things I'd still need in the few days before leaving. But one month before leaving?
The thing is, I don't really think about packing to get things to already get ready for the trip. I test-pack my backpack because it seems absurd to be able to fit all of my clothing into my 30l Bach backpack. I have never before been a minimalist packer. I think I usually fit somewhere in the middle between minimalist and having luggage that is too heavy for myself to lift.
But this time, everything I need for an almost three month trip to Bolivia, Peru and Cuba fits in one bag, with a few small things in an other backpack that is going to be my daypack. And a few things might end up in my boyfriend's huge backpack, but right now it looks like I don't need any additional space in his backpack, and I also don't only carry enough clothes for tree days. I actually can't quite wrap my head around it right now (Hence the repeated test-packing).

Here is how I fit everything I need into this small(-ish) backpack:

•  Most importantly, this backpack is cleverly built and is easy to pack. If the backpack is awkwardly built, the available space in it might actually seem a lot smaller.
• This is an old trick, but it makes a huge difference: Roll your clothes. They take up a lot less space that way. 
• Leave anything behind that you don't use. Had I decided to take a sleeping bag, I'd have to have a backpack at least 10 l bigger than the one I have now. Similarly, using a kindle instead of books, planning on layering clothes instead of carrying lots of warm clothes that then can't be used in warmer climate can save lots of packing space.

I'll post my definite packing list for this trip later, and a few things to consider when travel to cold and warm climates in one single trip.