The Romans could have pushed further North certainly. The problem wasn't one of possibility but one of motivation. The British territory was already the furthest North of the Roman Empire and the fringe of the fringe. If the raids into Britannia Inferior were more frequent and more problematic, and if an Emperor needed some kind of campaign to cement his legitimacy, and if the East was more peaceful and less threatened then I do believe it could happen.
However, it would probably be seen in hindsight as an expensive mistake unless they find some nice resources to exploit. If we look at Agricola's campaign we see the basic strategy. Hold the Scottish Lowlands across what will later become the Antonine Wall, and then push to the Firth of Tay. And then establish a string of forts up and around the highlands to the Moray Firth.
To hold the area, enslave large numbers of natives and replace them with loyal citizens and either move one of the legions in Chester North to maybe Newcastle or install a new legion bringing the total up to 4. It would be quite brutal an occupation, at least for the hundred years or so, until some signs of Romanisation comes into play. The Highlands proper could probably be left alone so long as they leave Roman Britain alone.
The right Emperor and the right incentives and it could happen. Getting that into place probably has more to do with PODs in the halls of Rome and Parthia than a POD originating from the islands themselves.