Moving Japanese anemones in Spring

I have two Japanese anemones which are in a way too crowded border and would like to move them now.  Can I do this?  I found a thread about moving them in July, but don't really want to wait.  I know they are meant to be invasive, but I've had mine for a few years and they haven't spread much at all - perhaps because they are too crowded ? Any advice very welcome.