Vine growing problems

[Mellifera]

I brought back two grapevines from Greece last year, small 1 foot long sticks with a few leaves. Leaves all fell off in transit.
I planted one in the garden, one in a huge pot on the patio.

In a few years time (I hope next year) we will get the patio redone and a pergola thingy attached to the back of the house over the patio and I planned to have those grapevines as shade.

Problem: the mini stick has grown to a 6 foot monster with several branches, they are outgrowing my supportive metal cage thing (Waitrose sold these a while ago, very pretty).

WWYD with it? Just let them grow back down the thingy?
Provide even bigger supporting stuff? I can't unwind the branches to put to a bigger support, it has to stay.
Help!?
I would provide a pic but I'm not at home, will post a pic later.

pic

Anyone??

I don't know about a new vine, but we have inherited a very old one, in our new garden. It has rampaged over everything nearby at an alarming rate.

We intend to prune right back to a metre stump in the Autumn and train next years growth over a pergola. I would support it as best you can, over the summer and prune it in late Autumn. You could aim to plant it in its final place, even if there is no pergola yet.

The vines we see in vineyards are especially pruned to produce grapes without much growth.

Thank you.
We planted one out where it will stay but slugs have eaten quite a bit and it is only half the size of the potted one. I'm also a bit nervous of planting both out in case the builders wreck them. The garden needs total relandscaping. We don't even know if the ground level will stay the same.
Will try and just let it roam, support and cut in autumn.

We had a vine growing against our fence at our last house. They just keep growing it you let them and just get all tangled up. They need something to grow around so you probably need more supports. We just used wire attached to the fence.

The first year I did nothing and it went mad. After reading a bit you have to cut them back very hard (we had a short trunk with 2 branches either side) but any branches you want to keep only cut to the 2nd knobly bit, a a few inches long. The grapes grow on these bits, the 2nd year of growth not new growth I think.