This reply will be equally long, and time consuming to read, enjoy! Thanks for laying out your lifestyle and goals, what I can do is give you a list of things to consider and things you will need to decide on. I will load a ton of links to relevant pages, some you may have read and some maybe not, some are a lot of fun to try if you are looking to live off grid. This is at least a starting place, feel free to ask follow up questions about any of it, here goes!
A ‘Tiny House’ is typically on wheels, but in our opinion, immoveable homes are better. If you are looking for a mobile tiny house, here are a few links to check out:
If you are looking for a stationary house, you need a piece of land to build on. I’m not sure, but do you have that land already? Great if so, but before purchasing a building lot I would check with the local municipality if they have a minimum home size requirement, and if that is a size you are comfortable with. Here are some pages to help.
Choosing between a slab on grade and basement – slabs are cheaper, more ‘eco-friendly, healthier and more durable. You can buy a prefab slab kit, or you can have one designed by an engineer and build it yourself (with your army of helpers) Keep in mind, depending on site conditions an soft costs such as engineering and permitting, one isn’t always cheaper than the other between prefab and hand made, so price them out.
To stay on budget when building a home, you need to carefully plan the steps ahead, see below.
We will have more news in the near future about innovative prefab kit homes that are LEED Certified and Passive House ‘ready’, in that they are of a quality that can meet those requirements. That’s a good thing for living off grid because it keeps your heating costs down, which In your case I imagine is likely firewood? Some solar heating options are linked below.
That is really just a start, you still need to choose a wall assembly, here are a few pages of material types that are available.
This is probably waaaayyy more info that you were expecting, and some you may have read before but I just wanted to make sure you found a few of our more obscure and interesting off grid articles. You can find all that stuff and more in the Ecohome Building Guide Pages, but also pop in any keyword like 'off grid' in the search box at the top of every page and you will find even more. Good luck!