The other possibility - and probably lightest option - is to increase insulation inside your quilt, e.g. down or climaloft clothing worn in camp. Or just a cheap fleece blanket. On the TMB, we carried a tyvek "blanket" to spread over both sleeping bags/quilts with a few tieout points to keep it place instead of spray biwi bags ...
I can barely fix a hole in my socks right now. If I attempted to add more flufff to my quilt I'd destroy it and it cost £200+. Also, it has down in it and it'd be nice to get synthetic on the outside for any water.
Just looked at https://www.adventurexpert.com/customers-outside-eu/ where I have ordered before, but they have a minimum spend of £135 to ship to UK. Seems VandP are your best bet if they have Apex 67 in stock. Their quality has always been good for me.
How about https://www.ultralightoutdoorgear.c...-agnes-kings-canyon-ul-synthetic-quilt-p13467 again when its in stock.
Looks like GramXpert is a pretty good option after all according to these recent experiences in the Buying from Europe thread: