Butternut squash plants

All seems to be going well in the greenhouse and vegetable plot but one thing that has really shocked me are the butternut squash plants - we only have 4 but they are close to 5 floot long now! Every day or so I have to move the tendrils away from lettuces and carrots and try to convince them to grow the other way!

Does anyone know how much bigger they are going to get in terms of length?

We have started to see some flowers but no fruit yet - so I figure they have a while to go yet!