Getting to a point of over-accumulation does tend to result in a lot of options that were not otherwise available during the time that accumulation was still taking place, and a person likely gets from 5 BTC to 6 BTC after a decent amount of hard struggles.. and sure there sometimes could come reassessments that end up allowing conclusions that 5 BTC is enough - and then recognizing that he has 6 BTC..
In regards to your suggestion that the extra BTC could serve as an emergency fund is not completely off point, since whenever anything is extra there are options with it - yet still it does not tend to be good practices to have your emergency fund denominated in something other than your own local currency... which truly having BTC as part of your emergency fund could lead to selling some of them at price points that are not very convenient.
But yeah even having 6 BTC rather than 5 BTC could cause the HODLer to feel comfortable to begin some kind of a
sustainable withdrawal strategy - especially since he has extra BTC. Even with a 6% withdrawal rate, there could be 0.025 to 0.03 BTC withdrawn every month... and it would take quite a while (several years) to deplete the amount down to 5 BTC.
I agree that bitcoin certainly should not be an emergency fund, as you may need to sell it in low prices.
I also see bitcoin as an insurance, in case things don't go well in the global economy or locally here in Brazil.
In this sense, bitcoin can save me in possible emergencies in the Brazilian economy. but this is different from an emergency fund
You are describing bitcoin in terms of a hedge function, so yeah that is a bit different from an emergency fund, even though each of us still need to consider various kinds of options that we have available to us in terms of where we hold our value and how much disposable income that we might have available to continue to add to our bitcoin investment and any other investments that we might have - while at the same time we surely have our monthly expenses, and there can be quite a bit of variance both in terms of how much monthly income that we can generate and whether our income and/or our expenses are varying to a large degree,
...and surely the more that our income and expenses vary, then the more likely that we have to keep some of our funds in our local currency in the forum of emergency funds, reserves and/or float.. which may well take away from how much we are either able to keep in bitcoin or to put in bitcoin.. and surely each of us are tempted by wanting to make sure that the extra value that we hold (even in local currencies) is working in some kind of way rather than either not gaining in value or excessively losing value.. and at the same time, we have to be careful not to get too greedy in terms of how much we feel that we need our capital to be working, because sometimes even those various funds that are held as emergency, reserves and float will end up serving their purposes. .including that the larger our bitcoin holdings, then maybe we are not going to want to be dipping into it at times that are not convenient.. but then we have to have money in reserves and float so that we dont have to touch our emergency funds either, unless an actual real emergency takes place.. ..so it would be a shame if we prematurely ended up using our emergency funds and then end up having to dip into our BTC at a time that was not at our own choosing when the actual emergency ended up coming.. so in a better case scenario world, we might well go 20-30 years or longer and never have to even touch our emergency funds because whenever we have shortfalls in cash we spend from our float and/or from our reserves.
Truly in every investment general there is always a need for other means of savings which could be known as emergency funds or reserve funds, although they are both two different things but sometimes can be substitute for each other, so actually in terms of Bitcoin investment emergency funds plays a very vital role because is actually one of the determining factor of your investment success because if there is an emergency funds there is no way any unforseen need will stand as a barrier on your investment because you already have other funds that will take care of those needs. Actually this has been one of the challenges most investors are facing because they always get overwhelmed by there investment and forgetting the things that should be put in place in other for there investment to stay strong such as the emergency funds.
And yes is very possible to go 20-30 years or longer and never have to even touch our emergency funds because we have a good float and reserves funds, in other to hodl Bitcoin for long is advised to have an emergency fund, float and reserves funds.