Yes, I think it's approximately as straightforward as building a SaaS company from scratch. Which is to say "non-trivial" but very, very within the realm of possibibility.
I've written a ton on this topic, on HN and my blog. So has Thomas, among many others.
Professional services can be very lucrative; film at 11. My lawyer charges $750 an hour and my accountant $600. I have no difficulty believing they have 70% utilization. I know there are HNers that find this difficult to credit. If you take nothing else from the 3 million words I've written, take "you can charge vastly more for your skill set than you do if you connect the deliverables directly to business value." (True for consulting, regular employment, selling products, etc.)
It's boringly straightforward to scale the business after you've done it once. Success breeds success; you ask your newly satisfied client for referrals and follow-on work, you use case studies made with them to target firms at similar or slightly higher levels of sophistication, you turn the one-off engagement into something that you can predictably pitch and execute like a restaurant can predictably cook eggs to order, etc.
I don't know if Patrick could do that, but I've been on the other side of deals materially equivalent to those numbers.
A 30k rack rate at those utilization rate is a high number but not an impossible one.
It is not a number you will get for software contracting. It's one you'll get for solving business problems that cost/are worth much more to your clients than that.
I don't doubt it. I've certainly seen people bill similarly (and obviously it doesn't involve writing that much code) - I'm just trying to put the pieces together in this context.
Just interested - does that mean that you've never actually been a full-time consultant?
And do you really think that it's within the realm of possibility to pull $30k/week for 35 weeks/year? (ie: $1m+ after your $50-100k in expenses).