Looking for bivy sack reccomendations

Contact Borah Gear he will do custom sizes.  Unfortunately he is not offering his event bivy right now.  MLD would be another good place to look.

@ matt
I have used both an Oware Gear bivy (branded BackpackngLight) @bivysack.com and a Mtn Laurel Designs bivy for winter snow camping under a pyramid. Both these bivies have waterproof floors and a water resistant top which I finds works fine since all I need to do is brush the snow that I happen to track into my shelter or brush off the frozen condensation that falls from the inside of my tent when I leave the shelter in the AM. I have also used the water resistant bivy inside snow caves. I like the zipper better on the MLD but the Oware Gear bivy is extra large and has room for my boots and puffy jacket and other items I like to keep out of the weather.
I have used a 3 layer Event bivy from Rab( Integral Designs) under my pyramid sleeping on snow but found I was sleeping too warm in it. Your experience might vary since our Sierra Nevada winter nights are warmer and I would think have a higher relative humidity than yours.

I should clarify that i’m looking for this bivy to keep my bags/quilts dry from condensation inside tents while winter camping.  I don’t intend to use it without a tent.

@ Matt
There have been a lot of threads about bivies and condensation here that you could read. Since often the source of the condensation is the moisture laden warm air from inside your bag that condenses on the cold outer layer of your bag, some folks report that use of a bivy actually increases condensation since the physical barrier inhibits the ability of the air to move.
I have used my MLD water resistant bivy a couple of times inside a tent when camping above or near the treeline and have not experienced such an effect.

Last paragraph: https://backpackinglight.com/forums/topic/condensation-issues-enlightened-equipment-quilt/#post-3614358