they wont necessarily be low on fuel, flights will fill up with fuel wherever is cheapest not every time they are on the ground.
If fully loaded, a 737 can fly for 5+ hours. 6 or 7 in some circumstances.
I agree it looks like Liverpool for them. I have a lot of love for Liverpool but assume they will now be stranded there for the night, far from ideal
in other news a Lanzarote to Dublin flight ended up in Bordeaux