Cottage manufacturers often are more accommodating to people of various sizes. They often make things to order and people needing off-sizes are often willing to spend a bit more for something that works.
Enlightened Equipment sells quilts (look into them) and bags for people up to 7 foot! https://enlightenedequipment.com/ https://enlightenedequipment.com/
They also sell a bivy sac but it only fits up to 6'6". Bivy's are not there standard business, but they may be willing to customize.
TarpTent sells some tents for tall people: https://www.tarptent.com
I would contact them with your desires/specs and see what they recommend.
MLD sell custom bivy's. They should be able to help you out:https://mountainlaureldesigns.com
*Note: I've heard a lot of good things about MLD, but I have never purchased anything from them. I have purchased and am very happy with stuff from EE and TarpTent. I don't have a commercial interest with any of the companies I linked.