Aubergines

My aubergines have produced very little food this year but plants look healthy, I was considering removing the few remaining flowers and putting my portable cold frame over the plants to see if they would over winter - they are next to a south facing wall though we do live in Yorkshire so they will have to withstand a Yorkshire winter. Would moving them in to a greenhouse be better? I thought the cold frame solutioon would cause less root disturbance.

Have also just discovered two peanut plants in my green house- I had given up on them completely having planted them in spring but I suppose the slightly less awful weather two weeks ago must have helped, Will they overwinter inside ready for planting out for a (mammoth harvest next autumn) any one have any experience?

Aubergines are like tomatoes, chillies, etc, in that technically they are perennials but are grown as annuals. Mainly because, in cooler climates, winter kills them off. A cold frame wouldn't keep them warm enough. You'd need at least a heated greenhouse. I know people who have overwintered them but in a warm climate. The results were mixed.