Federal election times are set by 2 U.S. Code § 7 as 1 day after the 1st Monday in November (of even numbered years). The law is from 1875 and from what I can tell is indeed nominally motivated by the voters’ need to first observe rest day on Sunday and then travel to their polling place. Keeping it and not having a federal holiday coinciding with it is largely aimed at keeping voter turnout low.
I very much lean towards the microfactory approach - locate a cluster of resources within reasonable belting/piping distances, design a factory which can consume the cluster’s entire production of the limiting resource (clocking others to match) to make 1 output or maybe 2, then provide that output to the rail network. Some production chains make it easier to have certain inputs taken from the rail network.
Within one of these factories, items are refined further for each floor they ascend but I rarely enforce a 1 product/floor rule - in particular I find it convenient with many Assembler/Manufacturer recipes to have an input that is directly fed from a single Constructor using clock speed to match production with consumption. This usually means each microfactory underclocks its most power hungry buildings a fair bit which keeps their consumption moderate. Each microfactory ideally has a single priority power switch to turn off its entire production chain if its consumption is becoming a problem and I set up a priority sequence for them.