Kodiaq TSI or TDI?

Hi folks, 

First post here so thought I'd start with a Hello! 

I've currently got a Kodiaq Edition 2.0 TDI 190 4x4 which is coming up for 4 years old, it's been a great car and has been really good for towing our touring caravan which has a MIRO of 1360kg and MTPLM of 1575kg. 

I've been looking at new Kodiaq and a local dealer has suggested that I don't do enough mileage to warrant a diesel (around 8-10k per annum) and has suggested getting a petrol version. I've always been of the thought that diesels have more torque so are better for towing. FYI... I probably tow once a month on average through. 

They've offered me a reasonable deal on a Kodiaq L&K 2.0 TSI 190 PS DSG 4x4 (I was orinally looking at a Kodiaq SE L Executive 2.0 TDI 200 PS DSG 4x4 but you know what dealers are like trying to get you to the next price point!). The torque difference is 320 Nm (on the TSI) to 400 Nm (on the TDI), I think my current one is 380 Nm from having a quick google. 

I guess my question is what do people think? Do you think I'd notice much of a difference? Would I regret not having a diesel? Has anyone got experience of towing with the 2.0 TSI 190 with a similiar weight van? 

Thanks in advance for your help! 

Joe