Sowing for Autumn/Winter Harvests

Every time I consider growing in the gh over winter, I'm disappointed. The frosts kill anything tender I grow and if I put something like chard in the borders they only seem to take off in spring when I want to  clear the space for putting up staging/sowing/planting. I have some beans and carrots sown in MFBs just to extend the season and I may sow some chard in pots to see how they produce, but you need and awful lot of pots of chard to get a few meals out of them. The upshot is.... I don't bother.

Trotting out those old excuses again, JJB.
Throw some fleece over your plants when frost threatens. You know you'll wish you had, at least, tried. There are winterhardy versions of many veg that you could try.

It's not really excuses just reservations based on previous experience. Fleece doesn't seem to cut it in minus 5+.  I know it sounds like excuses but it's my reality. I don't want salad stuff, brassicas are too big and all my favourites are summer grown. I'm not about to try to grow beans, courgettes,  toms and cucs over winter. I tried MT even with fleece it got frost bitten.
I've got a few MFBs going to extend the summer season and I'll start early next spring.
Plus it's a long way up the garden walking on a frost laden law which does it nor me any good,  (if it survives the drought) so everything gets neglected.  Let's just say I know my limitations.  If you can think of something really worthwhile growing overinter then do so, I'm open to suggestions.