For my build I picked up a 20'x24' army tent wall, rip stop pvc coated canvas at a surplus store, it's like new. I'll still be adding insulation and an interior fabric of nylon but I'm building for extreme cold. Yes, it's heavy, no problem with a truck and trailer.
What you select will depend on how it folds, sufficient storage space, the weight plays on the support system as well.
Silk is not a good material for a tent, you're probably thinking of nylon.
There is a good article on selecting a tent that talks about materials on EP.
Popups don't have to be square structures, I'm also concerned about high winds, 50/60 MPH gusts and snow loads, that leaves out the E-Z party tent types.
Youtube has videos on how to make tent windows ad doors.
You might consider a combination of soft and hard sides, tentage can be laminated into most panels that might hold real windows and doors and panels should be self supporting, IMO without stress on the material.
I'm considering using a upholstery wall material, under-layment or masonite with several coats with kilz, blue-board, insulated vapor barrier (used to make soft coolers) then the PVC canvas. The panels will fit close enough to allow folding but not be secured other than by the fabrics, top, bottom and corners. A half inch of foam rubber over masonite and under the interior fabric has been used in custom vans for smoother soft walls and headliner.
Corrugated plastic is also a contender, it's used to make outdoor signs, light weight and pretty tuff stuff, the runs in the corrugation can help with condensation.
PVC may have condensation issues, to solve that a layered approach can allow for seepage openings at the bottom of the lowest area on the outer layer. You need air flow, vent and a vent fan, one or more computer fans can do the job.
Good luck on your build and show us!
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)