White Rot - a few questions

As feared, about half of my onions have white rot on them - I'd been warned that there was white rot on the allotment site. I have a few questions and am hoping any experts out there might be able to help me:

1) is the crop salvageable? i.e. can I just chop off the bits with rot and freeze the rest of the onion? (I realise that the onions won't store in the conventional way).  Yes, that's fine

2) how do you freeze onions?! Do they need blanching? No.Or can I just chop, bag and freeze? Yes. Double bag to try to prevent odour spread.

3) I have leeks growing on the next door bed - are they likely to come a cropper? I don't know if white rot affects all members of the allium family to the same extent.

4) I LOVE all alliums, and am gutted - is there any way to grow them successfully regardless? Are there any resistant varieties? Would garlic succumb? Should I dump a pile of compost in one of my raised beds and grow them there? Some people are trialling the use of a garlic drench to fool the white rot but it's too early to say whether it will work.  I wouldn't try garlic itself on the site as that will succumb.  You could try a raised bed but be aware that the pathogen spreads through water in the soil so could easily contaminate the bed - and compost is not a good long-term soil replacement as it has little structure and fewer nutrients

All and any opinions most gratefully received...