I'm a little fat lady Wayne, and I survive on an average of about 1500 a day.
2,000 a day and I could be enormous !
Most slim women in the west do not eat 2,000 a day, regardless of what's claimed. They just cannot and stay slim. The more physically active may manage, but the majority do not, and the majority world wide do not. 2K a day is a Western idea.
Wikipedia claims 1800 as necessary and then comments about the figures not taking into account household wastage
I think it needs a different mind set, tbh. Those who live their traditional lives without the trappings of modern civilisation do not do so alone, they do it in family or tribal groups.
The OP asked if it could be done alone…..too many variables I reckon to answer definitively, except to say that it is not going to be easy except in the very best of situations, and those are most likely not the scene he/she envisaged.
If you stop thinking of meat as food at all, and trust me, vegetarians and vegans do. I could no more eat meat than I could eat another human, then instead of comparing vegetable sources of assorted 'necessary' ingredients to the ones from meat, you realise that the vegetable ones are fully complementary within themselves and we genuinely do not need meat to either live or be healthy, especially if one includes wild foods, and their yeasts, in that diet.
Farming makes life easy for both vegetarians and meat eaters.
Those who only hunt often starve, they need fat, and the kidneys and liver cannot process enough 'meat' without the fat to give enough calories…..look at historical population densities for evidence of that (rabbit starvation, etc., too), while humanity thrives when in areas such as those with natural wild grasses and legumes. The Fayoum for instance.
In a Survival situation, nothing changes for me re the food I can and will eat. Humanity has more than hunger to it's multi stranded psyche.
Most modern humans of the western world wouldn't have a clue how to hunt enough and prep enough to survive, any more than they would to do so on purely plant material.
Which plants could you gather in bonnie Scotland to provide you with your 1700 calories per day and what acreage of land would you need to support your family on through purely a veggie diet without modern industrial farming. I was a veggie for 5 years so have no issue with those choosing to not consume animals.
The op asked if you could survive on veggie diet. I have not found any evidence in the last 10 years of looking to support the hypothesis that it is possible to live as a vegetarian purely gathering the plant material from your surroundings. I would be happy to be proved wrong but there is nothing in this thread that proves one could survive long term on a veggie diet without 20th century farming and transport links.
The reason I am no longer a veggie is I have an allergic reaction to cheese. Makes eating out rather dull.