As long as it gets somewhere between the middle mark (90) and the mark before that, I wouldn't worry.
With both the original 1.1 engine and the replacement 1.2, along with multiple thermostats, I have found the temperature reading on the gauge very temperamental.
In this colder weather, it tends to edge toward the colder side on the gauge, even in a longer run out.
I've fitted brand new thermostats and the engine never rose much above the second mark on the gauge!!!!!
May be worth double checking the connection to sensor on the engine, just in case