Factors that will affect your range:
1, Speed, you reach a point where aerodynamics will result in more drag, therefore more power required, reducing range. 70mph will use more battery than say 60mph. There is a sweet spot. About 60-65mph I've found.
2, Weather, temperature, strong headwinds, rain, resulting in more use of heater, etc.
3, Driving style, it's fun to drive and easy to hit that go pedal, but use the power meter bottom right of dash to drive the most efficiently. Try to keep it at 10% or under for maximum miles/kWh.
4, Traffic. Stuck in slow moving traffic with the heater on in winter will drop the range.
5, Terrain, lots of hills will use more power. A regular long journey I make uses different amounts of battery as one way is more downhill, and the other way is more uphill. About 5% difference over a 90 mile journey.
6, Car settings, ECO mode, brake regen, heater/aircon settings all will make a difference if you're trying to maximise your range. Some people turn heater on/off during a journey, but I've found keeping it on constantly but at lower settings to be more efficient.
7, Battery preheat. Unless you live in a very cold climate (not the UK), then switch it off. Should only need it for sub zero temperatures. It eats battery range, and you would only need it to preheat battery prior to a rapid charge if the journey to the rapid charger is less than 30 minutes. If you're using a rapid charger part way through the journey, the battery will have warmed up sufficiently from the drive.
As others have said, if you were getting 3.4miles/kWh, then you should have got much better range than 90 miles. At that efficiency, a 90 mile journey (the one I make regularly) would use about 32-36% battery in this weather. I do have the long range battery, but even so, you shouldn't be using close to 100% of the battery for that distance.