The FOM website says the track is 3 m shorter from 2014. I reckon we'll get close to the 1:13.5 but won't beat it.
The pace advantage of the Ultra Soft to Super Soft was (I think) in the 0.5-0.8s range from pre-season testing, but that was different track characteristics to Monaco.
If we use Sochi as a benchmark for pace increase due to car developments, 2015 Pole was 1:37.1 and 2016 Pole was 1:35.4... a 1.7 second improvement! Of course Sochi is 5.853 km long vs Monaco 3.337 km so the increase due to car developments will be less. Monaco distance is 57% of Sochi, so lap time due to car development, likely ~1s. Car development+Tyre advantage=1.5-1.8s lap time gain...so may be they'll just beat the all time record after all?!?