Personally, I think Rome reached as far as there was any point in reaching, and attempts to go further would wind up as "why are we spending this much on something that isn't worth it?"
Arminius and his kind don't need to have the whole of Germania on their side to have enough to make it bloody and unprofitable.
Germany was full of mining in the Middle-ages, also there is evidence that even in the short time of occupation, Romans already started mining East of the Rhine. So there was some potential to exploit.
Also, HOLDING a territory long term was usually not Rome's problem. Their way of dealing with rebellion was in almost all cases successful (murderous) enough to establish a graveyard-calm for generations afterwards and usually, just more Romanization.
A localised, and as to the POD, failing Arminius revolt would be a flash in the pan, and just like Vercingetorix or Boudicca, would probably not have spawned decades of Germcong-activity.
The expensive thing for Rome were borders. That is the problem with Britannia. It always needed three legions unless you conquer Caledonia. But there is no point in doing so as you still have to guard the coast against raiders from across the North Sea.
If the Roman border moves from the Rhine to the Weser/Bavarian forest (best of all not in one step), you move the border legions with the limes, perhaps keeping one in reserve somewhere central. Over time, the latter becomes less necessary. Generally, the cost of the army is its personnel. If they have to slay a Germanic tribe once or twice, that is not costly.
If you move the limes to the Elbe later on, or even to a short Limes across Schleswig-Holstein, you do Roman Britannia a huge favour.
To me, the crucial question is: how much of the external crisis points do you avoid by preventing some of the Germanic tribes from develop during the 2nd and 3rd century into the large-scale units which start to become a power factor?
What if, by AD 150, you have taken the Marcomanni out of the equasion, but also what is to become the Alamanni, the Saxons and the Franks? What if you can punish the Jutes at their doorsteps instead of building and manning the shore fortresses of late Roman Britannia?
Would we have a cascading effect of a slightly easier situation in Europe -> better showing in the East -> better ressources on Danube and so on and so on.
What if you later on have a lot more (as we all see not THAT vital) space to trade in order to get foederatii under, such as the Gothi and the Vandalii - and that while being generally more fit as an Empire?
#### ASB wet dream #####
Final limes running along Vistula - San - Dnestr, the Southern half of this limes would be easily suppliable by a logistical network based on Byzantium/Constantinoples.
However, just a few ideas...