I live in London and have 3 vines. The 2 I planted grow and established very quickly. I grow both outside but provide some protection for the root of the one that's in the main garden. I find that if I prune back to growing spurs I getter a better crop of bigger grapes. If I leave the plant unchecked I get a hugh crop but the grapes are very small. I tend to prune early spring while the plants are still dormant. I inherited a third which was overgrown and suffering badly from mildew when I got my allotment 7 years ago. It had small bitter fruits which went mouldy quickly. I cut it right back and then used the same principle as my home vines and now find that I get a larger quantity of good size grapes of a very good flavour.
I suppose it depends on where you are, but vines are generrally easy to grow and maintain and relatively problem free.