People have posed this question to me many times over the years...

People have posed this question to me many times over the years in my business, and my response to "can you keep up if it goes off?" has always been "great problems to have!".
I don't say the above to be dismissive, just to say of all the troublesome scenarios we will run into, this is the best.

Obviously customer experience is extremely important, as it affects repeat business, and CLV is the most important metric of a customer.
Getting them coming back time and time again is what really generates the long term profits, as you don't have to spend the same to get them, as you do to keep them.

The great thing about digital businesses on the DTC side is that the funnels you build to bring in customers are like a tap, and you can regulate them instantly (still some lag, as the advertising from last week and yesterday is still feeding customers into your various channels, but much faster than bricks and mortar).
Doing too many sales on a particular day and worry your logistics will not keep up? Just reduce Ad spend in realtime, and they will quickly slow.
It's also important to remember that when driving large volumes of traffic through your various channels, you are paying for everyone of them. By reducing Ad spend, you can increase the ROAS, as when you reduce the target audience, you start getting the easier to acquire customers, and those low hanging fruit are much more profitable.

With our own logistics, and by building the systems ourselves it also allows us to inform the customer on the progress of their order much better than when using third parties, so that will also allow us to keep them more content when there are delays or when lead times stretch.

I'm very excited of what's to come over the next couple of years.