Well, assuming you cannot load/unload and move in the same turn …
Usually, the US have some transports in the Atlantic (North Sea), build infantry in the US, which on the next turn moves to Canada, from where it is shipped to Norway and unloaded the following turn. The trannies stay on these coasts, next turn move back gather more Inf, return, unload etc.: a constant flow of soldiers from the US to Eruope
If you can’t load, move and unload in one turn, this cycle still can work, but needs more resources (a second bunch of trannies). This means you either start with not a flow of soldiers but a trickle, or you have a “pulsed” flow every second turn.
Of course, the first pack of soldiers will arrive one turn later than “usual”, as it has to spend one turn on board the trannies.
With the trannies it would be one bunch stands at canadian coasts and has loaded its Inf the last turn, the other stands near Norway and is empty. These bunches exchange their positions and load/unload.
One thing that came to my mind…
You can load troops onto a tranny during Combat Move, so, as long as your tranny starts next to those troops, it effectively can load (in CM), move and unload (in NCM). Not that it changes a lot (not of the scenarios discussed so far at least), you “just” need to double up the number of trannies to do the same work like “usual”.