I live in an all-electric house Auzz. It works largely because I have massive levels of insulation, triple-glazing etc.
Not easy (or cheap) to fit in your case. As for renewables... I fitted an air-source heat pump with underfloor heating.
Again, not easily done with yours. (Also, the AS heat pump is quite expensive initially to buy.)
Do get rid of the storage heaters and consider modern replacements. These are individually controlled, and, of course, are quick to respond.
Some feature a small measure of "storage" which quickly releases heat while the heating elements crank themselves up.
"Dimplex" are worth looking at. Also, several German makes (they are widely used in Germany and Scandinavia.)
I'd advise a bit of good old Googling ("electric heaters")
Here's just one example......
https://www.dynamicheaters.co.uk/?gclid=EAIaIQobChMIo_f11Nvo6wIVBKp3Ch1wbQfsEAAYAiAAEgJVZPD_BwE
Don't expect them to be cheap, but, you won't need very many, and you won't have to do it again ;o)
They run off a normal socket if necessary.
It is tempting to have your gas connected. A small "Combination" boiler would give you instant hot water, and run several rads. However, installation is disruptive and costly overall.
Google the electric heaters and do your sums. Then compare to a quote from your friendly local heating installer for a gas system.