There is no such thing as being over invested in bitcoin. Pour all that filthy fiat into this imaginary digital gold token shit.
Nobody has ever gotten rich, from not taking any risk

Well, you are not "over-invested" until you are.
I would rather NOT have to come across any kind of scenario that I am forced to sell my BTC at any time that is other than my choosing. Surely, once your BTC become sufficiently profitable, then at that point, you don't really mind that you might have extra value in BTC.
Let's say that you have $100k in BTC value and $8k in cash, but you unexpectedly run into an emergency expense that is around $20k. BTC prices are in a dip, but you might be fucked because you are forced to sell off some BTC, at a time that is not of your own choosing, and worse if BTC is in a dip during that time, but surely better if your BTC are profitable rather than unprofitable when you are forced to sell some of them to cover your unexpected expense. Then as soon as you sell to cover your expenses, BTC does a 3.5x in 3 months and during a period in which you don't have enough of a cash flow to replace any of the BTC that you had been forced to sell during the dip. Sure would have been nice to have had other resources to draw from for that $20k expense, rather than having to draw from your BTC stash during an inopportune time, right?
Sure, my example might not be extreme enough, but you should be able to recognize what I am trying to say... you could end up getting wiped out of your BTC investment.
I have said, several times, that I had purposefully invested in BTC in a much higher than expected proportion than my comfort level (which is another way of saying overinvested) because I have wanted to feel a lot of comfortable in selling BTC on the way up. That is part of the plan to be able to skim off a few BTC here and there on the way up, and in that way, I feel comfortable with my level of overinvested.
So, surely, overinvested is possible, and each of us has to determine what kinds of income/expenses s/he has going on in his/her life in order to figure out what kinds of resources that we are going to be able to draw from when some of the unexpected expenses might end up playing out at the most inopportune times. Yeah, things are going all good and fine and thinking that we have cushions here, there and everywhere, and fucking bitcoin dips 50% and then 65% and then 85% and we thought that the bottom was in at 50%, and in the mean time, we have real world activities going on that could cause us to have some unexpected expenses taking place at the same time that BTC's price is dipping and at a time that we have already used up a large amount of any spare cashflow that we had in our sock drawer.. that is looking pretty sparse during those times of need. Why the fuck do I have to pay that tax? Why did they store gasoline in the closet? why is my new lambo/leer jet parked in that location, and why wasn't the insurance up-to-date? Fuck? Is the world against me, everything negative happening at the same time?
Yeah, shit happens. Especially if you do not adequately pee pare ur lil selfie.

Excellent advice and a rational way to look at your investments. I was just joking around about over investing. Even though it's true you have to take some risk to eventually get ahead, but investing in Bitcoin is in my opinion risk enough.
However the example you mention does not really apply to someone of my age, because most of my generation do not have 108k in savings/investments. I do not run into emergency expenses around the 20k. An emergency expense for me would be around 1-2k which I will be able to cover even though I have around 90% of my wealth in BTC right now.