You really need to check the specific gravity to know if fermentation is done. Beer can "off-gas" CO2 for some time after fermentation is complete, particularly in a temperature shift from cold to warm. Colder beer holds more CO2 in solution. When it warms up, CO2 comes out of solution. This could be the bubbling on your airlock.
But to answer your question, yes, colder fermentation temps can slow down fermentation, so it could be that too. Check the SG to find out.