Almost none I'd say, at least with the right technologies. Given that most things are automatable, farming, government, manufacturing, maintenance, etc. One could build tools, robots and AI to handle most of the tasks. Farming through automated vertical farming or aerophonics. Robots will auto collect, reseed, process, package and distribute the products. It can already be done but I guess theres not much pressure or incentives to do so, and other traditional farmers will be left in the dust. So if we had to, we could do a bunch of things like this.

Cars can already drive themselves and 3d printers can print houses from scratch, and many things too.

So with maybe 100-1000 intelligent and educated individuals, I think it is not only possible but quite practical. They could start small and build up what they have, and without any bureaucratic burden or needing please any side, they can move quite fast and get things done.