Yes, we now have the relatively cheap technology and devices to create a widely self-sufficient strange tech level mix breakaway/parallel society.
Power: HelioVis solar thermal systems, conventional solar, hydroelectric, wind, biogas, geothermal and the next gen Quaise energy geothermal tech.
Fuel: Hydrogen electrolysis, biogas, woodgas.
Sewage: BioRock filtration systems (non-electric)
Water: Atmospheric extraction and boreholes, solar desalination near the coast.
Food: Solarfoods.fi Solein solar protein, algae from bioreactors, EZGRO vertical farming system towers, some limited animal husbandry and potatoe towers, aquaponics.
Building materials: hemp, bamboo, wood, stone, rammed earth, straw bales, car tires.
Clothes: biopolymers from algae, leather, hemp, linen, wool.
Medicine: modern medicine is a scam anyway. Peptide synthesis machines and soon 3D drug printing, Rife machines.
Only electronics and metal ressources are bottlenecks requiring external trade.
All of this can be realized with just 500 - 1000 people and 50 - 200 million USD start capital. (50-200k per person).