The dangers of overwintering ...

I have five good-sized pots sitting in front of the north east facing double glass doors that lead onto the deck. In them I have, or rather had, several tomato and several chilli plants. Last week I took them all out onto the deck to give them a good water. At 4am I sat bolt upright in bed, expletives pouring forth. In shorts and t-shirt I raced out and brought the poor creatures back into the house then stumbled back to bed.
It was a sorry sight that greeted me when I got up later that morning. I discovered we had had a -6°C night! The chillies had melted, almost literally, and the tomatoes were burned to a crisp. After a couple of days I carefully pruned away all the dead tissue and was surprised to find that all the chillies still had healthy looking leaves around the base, a few of the tomatoes likewise, though three, perhaps four were completely fried, and one tomato, astoundingly, looked totally untouched though its pot companion was fried like the rest.
Life, it seems, is tenacious.

Phew, you were lucky Ray. It does show that chilli plants are quite tough. I overwinter mine on an exposed north facing verandah.

I was wondering if I really need a totally enclosed green house or would protection on three sides be enough to stop the cold wind.

I am also toying with the idea of eggplants as indoor plants over the winter.

It's not necessary to have a totally enclosed greenhouse for frost protection. My pots are doing very well on the balcony - which is enclosed on 2 sides. As long as the icy wind can't get at the tender leaves it's fine.

I do want a greenhouse, though. Mainly for all the vegetable seedlings that I start in winter and get to quite a size before I can plant them out in spring. My windowsill is not big enough to house them all. And the balcony is not enough protection for them at that stage during the nights.

I've got some peppers overwintering in the greenhouse - not doing much, but I've got an eggplant sitting in its pot outside in the wind and cold and it's bearing fruit! Nature is queer.............

My daughter lives out in the back blocks - freezing cold there in winter. Had some pots out on the back steps one year - was doing some trimming etc - forgot them - same thing - woke to find them in sorry state. They freeze on her verandahs and have to go in the shed.

Glad they weren't a dead loss to you.