The break thru time for rural electrification in Sweden were during the first world war when our neighbours were busy killing each other and we had smaller food riots. The immediate need was mostly to replace the kerosene for lamps that no longer could be imported from USA. But most of it was anyway done with three phase power with thin gauges to provide for motor power on farms to replace steam-locomotors.

This was 90 years ago when we had an economy weaker then Mexicos today but with nearly no corruption.

The electrification of the rail system were likewise rushed during the second world war to save coal.

If a grid could be built from close to zero during wartime nearly a hundred years ago it can be maintained or built from zero today with resources a small fraction of for instance the current US economy.

The grid and any non fossil power powerplants will be the crown jewels of any post peak oil country or power company. I find it more likely that there will be a small poor cottage for every 100 high tension poles with someone getting a free 16A and minumum wage as pay for daily power pole inspections, pole painting and manually moving the lawn around the switchyard rather then the grid deteriorating.

One intresting piece of information is that modern technology both can make grids more fragile and robust. You can simulate and optimise so that you can run the current equipent closer to its margins. And you can build in smarter automatic systems for shedding load or decoupling parts of an overloaded grid to minimise the size of a power outtage. A large problem with such smarts is that they are hard to test and you might end up creating new kinds of faults.

I have not heard abot micro grids, subgrids etc in Sweden. But there is intrest in iceland running of random parts of the grid after a major fault. And house turbine running of condensing powerplants, mostly the nuclear ones, to faster get them back on the grid after a major fault.  I do not think that anyone exept odd individuals plan on running a local grid as a normal situation.

The rules for adding small generators to the grid are reasonable. This might have to do with the wind power installations. I have heard but not read that we now also have code for allowing emergency generators in teleco stations, hospitals etc to bid on selling peak power to the grid.

The deregulation left the almost rediculously large cold snap spare powerplant capacity withouth any economy. We mostly hade about 35+ year old oil fired condensing powerplants built before the nuclear plants that were run for a few days or a week every other year or less. Some of them are now scrapped others are bidding on providing spare capacity that is paid for by the transmission fees on the high tension grid. But we now have too little spare capacity since absolutely everything has too work to handle a statistically 10% risk winter cold snap.

Most of the local Swedish investments are in upgrading the nuclear powerplants, more electricity production in the pulp industry, more combined heat and power plants for district heating using natural gas, garbage or biomass as fuel, wind power and uprating of the grid. The grid uprating is mostly adding 400 kV and HDVC links to get rid of bottlenecks and massive cablification of the rural distribution to make it weather proof and to compensate for the lack of locally living and workig maintainance staff. The most uncertain plans seems to be massive wind power investments and new natural gas pipelines.