b) If a country like Germany can't, within a couple of months, produce something as simple as resistive heaters in significant numbers, something must be seriously wrong. They consist of a cheap case, resistive wire wound into a coil, a fan, and a couple of switches (main power switch, safety switch that turns it off when it tips over). If a design takes 3 minutes to hand-assemble after the easily automatable parts (e.g. stamped sheet metal case, coil) have been made in great numbers, then a single factory with 100 workers will churn out 16000 per 8-hour day, or a million in 3 months.

c) even if Germany can't, China can. Maybe not enough for everyone but enough to make a significant dent in gas consumption, together with the ones people already have

d) everything that uses electricity is an electric heater. Worst case, heat a large pot of water on the stove.