not sure what your intention is to let it keep growing, wether it be to keep the buds fresh while you work on trimming or if its just to try and let the plant get bigger and still have some smoke while you wait. but there is a certain point in the plants life where it actually will start to lose its potency so make sure you harvest once the trich's are of the appropriate color. think of a bananna when its green you can still eat it but the flavor is a little less to be desired (with Mj the taste/potency is a little less than desired) as the bannanna ripens it begins to taste better, once the bananna is fully ripened or at its peak of ripeness it begins to degrade, well your MJ plant will do the same. so just dont wait too long.
with that being said, first off in alot of cases the main cola will be "Ripe" before alot of the lower nodes, and yes you can cut off parts of the plant and the plant will continue to grow.
my advice is to only do a little at a time, maybe 1-2 branches and if your doing the main cola just cut that and no more for a few days. the reason i suggest this is because the more you cut off the more you stress the plant. the more you stress the plant the more it slows down growth, by just cutting a little at a time as they ripen it wont stress the plant much and will free up more resources from the plant to grow them lower nodes, will also allow the light to penetrate the plant a little better.
im no pro so take my advice with a grain of rice, but hope i could help