Ah yes I suppose by my logic it would be like saying, I went to read the book but didn't however this isn't the case. So the fact that the FRANCE trip happened is always true no matter which you use. However if you used the DEFINITE it couldn't mean that you ever came back. Like one of the earlier comments said, would it be then possible to use ехали to denote that you never came back (although I guess when put in context that could also be shown using the perfective, as a complete trip could also mean a complete move to France).