Its a gamble dude... you could map it and add 200mb more boost and the turbo could fail straight away, it happens. The transmission is not too much of a worry on the auto boxes imo.
I have a Passat 130PD 6speed taxi with a remap to 175bhp 310lbft and over 315k on the original turbo running 1.6bar for the last 5 years on the other hand I had a mate with an auto Passat 130pd running 1.6bar for 4 month and turbo failed with less than 120k.
I tell every one to expect issues from a remap but not from the remap software, if a turbo blowing, clutch slipping DMF failing is going to cause them travel issues or hardship then dont remap the car.
If you go to get a remap on a 175k TDI and your expeting the turbo to fail and have the ££ to get a new one and you can get your head around its done 175k so its going to need a turbo one day.... then go get your car mapped.
As for the engine block and head thats going to be fine for spaceship miles with a remap...
Its the risk you take, all I can say is the majority of TDI remaps with 150K+ go away and last without any issues.
Nick