I have the 1.5tsi engine in my Audi A3, that is lighter than your Octavia estate. I tow a longer, wider and heavier Eriba Feeling 425 with it.
I am aware that the car is comparatively light with an 85-90% ratio when loaded for our 4 weeks long summer trip, but with 25 years and 50K+ miles towing experience I load the van sensibly, ensuring a nose weight of 60/65kg and keep to about 55mph. I find with a heavier nose weight the car does not feel as balanced as front end traction and steering response is compromised.
The problem I have is keeping the speed down, as I find the engine is very flexible and willing to pull up the steepest of hills.
With my previous 1200kg Triton I typically averaged 34-36mpg and twice managed 40mpg.
With my Feeling at typically 1350kg I typically return 32-34mpg, with a best of nearly 38mpg when I initially collected it, but it was empty.
I am perfectly happy with the engine for towing and everyday use. When I come to replace the car I will start by looking at the same engine in a Skoda Karoq.

Colin