No way a socialist party is going to merge with a neo-liberal party. Not everywhere has to be just like the US.
No way are they going to merge, I agree but it's not because of an irreconcilable ideological gap. The NDP is a market socialist party at its most radical. None of its leaders support the abolition of capitalism or nationalizing all business/transferring ownership of business to the workers. They merely want more welfare. People with such views often work with or within neo-liberal centre-left parties, including many people currently already in the Liberal Party.