The deepening energy crisis has prompted Georgian President Mikhail Saakashvili to cut short a visit to the World Economic Forum in Switzerland.
High winds and bad weather cut a high voltage power line, pitching the eastern half of the country into darkness, electricity officials said.
The capital, Tbilisi, was also without electricity after a unit at a power station collapsed under the strain of having to work at full capacity.
Georgia has been struggling to cope with limited supplies of natural gas after two explosions on Sunday hit a supply pipeline from Russia.
Difficulties in arranging extra gas imports from neighbouring Azerbaijan also contributed to the supply crunch.
Amid the shortages many Georgians have been heating their homes with wood stoves or camping gas, as they struggle with sub-zero temperatures.
"The electricity went off at one in the morning and since then we've been freezing. It's awful that the authorities can't solve this problem. What are they there for, if the whole country is freezing?" pensioner Irakli Gogokhidze, told news agency AFP in Tbilisi.
Housewife Keti Rurua complained she had queued for two hours to buy a canister of gas to heat her home.
"There are old people queuing up who don't have their own cars to carry these heavy canisters," she said.
The head of Mr Saakashvili's administration announced a clampdown on speculative profit from the sale of heating materials.
"Certain traders in gas and kerosene have tried to increase fuel prices.... The prices of liquefied gas and kerosene should stay at the same level," Georgy Arveladze said on national television.
Frosty relations
The energy crisis has brought a new chill to already frosty relations between ex-Soviet Georgia and neighbouring Russia.
President Saakashvili has accused Russia of deliberately blowing up the gas pipeline to apply political pressure on Georgia's pro-Western leadership -- a claim denied by Russia.
Georgia and Russia have long been at odds over the separatist Georgian region of South Ossetia, which Georgia accuses Russia of backing. Sunday’s pipeline explosion occurred in the Russian province of North Ossetia.
Alternative gas imports from Azerbaijan were disrupted on Wednesday by technical problems at a pumping station bringing gas from Russia to Azerbaijan, Georgian officials said.
Georgian Foreign Minister Gela Bezhuashvili voiced suspicions about that breakdown, saying that there had been "too many technical (problems) at the same time".
As repairs to the Mozdok-Tbilisi pipeline were continuing, Russia’s ITAR-TASS news agency reported further damage had been discovered that would require additional repair work, quoting a Gazprom official.
Russian prosecutors say the explosions were caused by a terrorist attack.
Europe freezes
Meanwhile, frigid temperatures have also gripped Ukraine, which like Georgia has been affected by the Russian gas pipeline explosion.
Forty people died overnight on Wednesday as a result of the extreme cold, bringing to at least 181 the number of deaths since temperatures plunged last week.
In Poland, the most recent 24-hour toll was 10, for an eight-day total of 63 dead. There were also deaths reported in Croatia, the Czech Republic and Romania, which registered 45 weather-related fatalities in six days.
Especially hard hit during the last eight days have been eastern Europe's homeless people, accounting for roughly half of all the freezing deaths reported.