I've encountered such TFs a couple of times. Lots of DDs, several CAs and CLs and some small troop transports.
I always engage them, the escorts so far never posed a real challenge. Just yesterday I attacked such a TF in january 1942, sinking a CA, one of those seaplane carriers, and four transports without breaking a sweat.
I simply placed my boat in front of the TF, let the DD screen pass over me (at periscope depth, engines stopped, rigged for silent running, while a DD passed me at 100 yards distance), then fired my torpedoes at distances between 400 and 800 yards.
And once you're inside a convoy/TF the AI has even bigger problems finding you.
Ah, and welcome to SubSim!