I hope your plans work out for you. Just out of interest, back in 2016 I spent 35 consecutive days in a small piece of woodland that I owned (still do) in Sussex. Daughter and granddaughter had gone travelling abroad so I knew I wasn't going to get people flapping whether the old boy was safe and sound.
My trip was never intended to be a full time escape, just a prolonged stay in the wood. I cheated, as I ferried in Ration Packs prior to setting up camp. Generally speaking 2 x 24 hours Rat packs will last me 3 days and I also took stuff like Nido powdered milk, Bacon Grill and various pasta stuff and soups by Knorr. As I say, it was never intended as a live off the land type exercise...and being a wimp it was August and first week in September.
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I'm a great fan of cheap kit...that works for me. My Eurohike tent that I've used for years. It's mixed woodland, a lot of Ash and Hornbeam and some Beech and Hazel too.
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There is a Medieval Well in the wood, the wood was once coppiced to feed the furnaces of the Sussex Iron masters with charcoal.
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The water is clear and cold even in Summer, but I always filter and then boil it before use. I've used it for years and never once suffered any ill effects.
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Water run through a good quality filter into a ready use Ortlieb bag.
Rat Pack beans and Sausages which is about the height of Sax's culinary skills..
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But to get back to your plans. I appreciate all woodlands vary in the Foraging opportunities they present, my wood is good for things like young Beech Leaves, Blackberries, Ramsons and Funghi (not for me though). I have a reasonable knowledge of available wild foods but I have to say I would have found it a real struggle to find wild food in sufficient quantities to live off comfortably, and I had access to ( Not owned) close to 300 acres and that was in August.
If you are able to grow perhaps root crops in reasonable quantities and preserve them, then life would be easier long term. Wild game is also a possibility.
I would have been sick of eating Venison if I had been in a survival situation..
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My time was 'Play time' really. 5 weeks of good weather, plenty of rations and enough wildlife and camp chores to keep me fully occupied, and I just love the isolation of being on my own. I was reluctant to return to every day life initially but then the weather broke and the Tea bags reached critically low levels, so I packed up and hauled my kit to the farm where I had left my transport
The experience was good but for me personally, I would definitely take a different approach to basic planning and other matters if I was going Off Grid permanently, but I wish you every success with your plans, Jon.