Polytunnel - grapes

I’ve seen grapes grow on a tunnel.

The vine was planted out through the side of the tunnel outside with the main vine in and up through the tunnel supports. It produced grapes most years.

Got one in Lidl or Aldi about six years ago and after the first year settling in it has produced good crops of grapes each year. Posted a video of the first crop here. I read that planting outside where the roots can get properly cold in the winter is better as the vines do better when they know when winter is. Mine is planted so close to the edge of the tunnel I think it gets to know it is winter fairly clearly and it got some frost damage for the first time I remember earlier this year but has recovered well. I read that they crop better when kept well pruned but I have been a bit haphazard about doing it and there still has been plenty of grapes. They are Merlot which might be a bit thick skinned for eating but I think they taste nice and have to give some to the birds since I can't get round to eating them all most years.

I have a vine in a big pot in my conservatory. I am considering moving it to the polytunnel as it only produces a few bunches of small grapes.