Okay let's take this veg by veg assuming your 'friend' lives in the UK...

Winter hardy peas will do fine and start growing early next spring, unless your friend ives in the north of the country in which case they will sit in the cold, wet earth and rot, or the mice will eat them

This is the wrong time of year to be sowing seed of broccoli or calabrese (most people appear not to know the difference!)

Cabbage, bit late to sow seed of spring cabbage but it might work.

Onions, assuming they are sets not seed and that your friend lives in the SE of England they 'should' be okay.

Might I suggest that your 'friend' joins GoY and asks their own questions.

We usually plant out seedlings of broccoli, and sprouts, etc. in early autumn here, and have never covered them with anything but 24" of snow! I think we probably get colder winters than the UK, too. They seem to thrive as long as they are well established and growing strongly before the first frosts come. I generally end up picking my Christmas dinner vegetables with the aid of a snow shovel. The onions won't really start to develop until the spring anyway - we won't be planting our sets out before the beginning of November: they fact that they are already planted when the warmer days begin just gives them a head start next season. You just need to be sure that mice or voles aren't going to come and dig them up before then! Not sure about the peas - I generally plant mine in early spring, but I'm sure it's variety dependent. I'm sure there's someone out there who will know for sure, though. Good luck!