There are many open questions concerning E-V13, as you can read. The main problem with your lineage is, that its rather rare and all so far tested English people are recently related. And I mean very recently, because you people below E-BY6113 could fall well into the historical time frame of established surnames. That is a very young date, we're talking probably about the 1500-1700's timeframe.
On the one hand that's great, on the other this tells you little about where your paternal ancestors lived 1000 years earlier. I would guess that E-BY6125 lived in the North for long at first look, but new finds and samples might change that. However, it looks good for your lineage to have been North West of the Alps, to put it that way, well before the Roman provinces in Gallia came about, probably with the Iron Age transition, spreading among Celts and/or Germanics. But that's just my best guess based on what is there now, it could have been even earlier, or somewhat (not much) later. You'll probably see once more people test. Those at FTDNA which tested so far won't help a lot, because they are too close. They are nice for a surname project, but not for your ethnic lineage origin project. Because for that you need matches which are either more distant or from different countries. Like if suddenly 5 Bulgarians with a historical TMRCA for the Roman Age would pop up, this would be a game changer. But as things are by now, it doesn't look like that will happen. Earlier, probably, but Roman Age, rather not. Yet the case isn't closed yet, you have to pray and hope for luck, to get the right matches which might allow you to get more out of it.
This very useful tool gives you an impression of how things look like, roughly, with the currently available data:
http://scaledinnovation.com/gg/snpTracker.html
But just keep in mind, every new ancient or modern DNA sample can make things turn around.
