Calling all armchair generals! Boudica's Last Stand.

[Nathan Ross]

That assumes Watling street isn't the most obvious route, we differ there.

Yes. Although if a general wishes to march against a massive tribal rebellion threatening one of the most important cities in his province, he would take the quickest and most direct route, surely?

Unless he wanted to detour immediately to London, he would not continue down Watling Street south of Mancetter or High Cross.

If he learned of Colchester's fall only when he reached Mancetter, let's say, he could force-march down Watling Street to London in about five days. 

But unless he somehow knew that he was intending to retreat again all the way back into the Midlands, or planned to do that, he would not be looking at sites around there to fight his battle.

Some more likely alternatives south of Towcester here

The direct route from Wales to Colchester goes via Godmanchester, up the top right quadrant of that map.

The point is (and we've been through all this many times, of course!) that we can construct plausible narratives to bring Suetonius Paulinus to pretty much anywhere in southeastern England. Your idea of a dash south and then a regrouping in the Midlands, coupled with an Iceni return to their homelands and then a push west, might indeed be the case - I can't see why a battle would be happening in the Midlands if any of these things did not happen. But generally I prefer simpler solutions to these problems, requiring fewer additional elements to those outlined in our sources. That means looking at sites in the close vicinity of London and St Albans.

We are unlikely to agree on either of our preferred options, so unless and until more evidence comes to light, or somebody else offers a truly compelling alternative, we shall have to hold our positions, you in your defile and I in mine!