Bought a rather spendy cumulus double quilt to use with my partner recently - https://cumulus.equipment/uk_en/quilts-and-comforters-comforter-xl700.html
But tbh we've never really got on with it. Always end up feeling a little drafty in it, with one person nicking the cover. We haven't messed about much with trying to use elastic to fasten the quilt down yet, but it feels like a massive faff. We end up using two summer single bags and the quilt on top at the moment, which just feels ridiculous.
I think a footbox which the mats could slide into (or even our feet could slide into) would really limit the ability of the bag to slip off one person's legs...
Can anyone recommend someone or a company which could make the modification, before we sell it and get two single bags which will zip together! I don't know if it should be elasticated, with a drawstring, insulated or not...and i think someone who has worked on lots of sleeping bags before would know what to do!