Your "if" is completely unfounded. Outside of China infections are not following any exponential trend at all.
The Chinese government’s senior medical adviser has said the disease is hitting a peak in China and may be over by April. He said he was basing the forecast on mathematical modelling, recent events and government action.
Dale Fisher, chair of the Global Outbreak Alert & Response Network that is coordinated by the World Health Organization, said that predicted “time course” may well be true if the virus is allowed to run free in Wuhan.
The flu-like virus has killed more than 1,100 people and infected nearly 45,000, predominantly in China and mostly in Wuhan.
Singapore has reported 50 coronavirus cases, one of the highest tallies outside China, including mounting evidence of local transmission.
[...]
Asked why there were so many cases in Singapore, he said there were comparatively more tests being conducted on the island.
“We have a very low index of suspicion for testing people so...we do have higher ascertainment,” he said, but added that there was a lot about transmission of the virus yet to be understood.
I'm not sure what to tell you. Unless you think that this virus somehow only targets people living in China, it's only a matter of time before it takes hold in other countries. This is not one that you can simply quarantine and isolate away like SARS. This one seems to be communicable at the earliest onset of symptoms, or even perhaps before.
If the rest of China looks like Hubei in a few weeks, we will be in pandemic conditions throughout all of China. If other countries start to look like China in a month or two, we will be in pandemic conditions throughout the world.