For winter use, I have a somewhat unusual take but that might give you a product that's clearly distinct from competition:
I don't wear knickers or long tights with chamois built in; I almost always use chamois-less tights over regular shorts. (That lets me mix & match rather than having pricy gear that I only use a few months of the year.)
Lately I've been using the liners from MTB shorts which have thinner fabric so the combo is less bulky, but they rarely have very good chamois.
So my suggestion would be to make liner shorts with a very-high-quality chamois that go well under tights or paired with MTB "baggy" outer shorts. Great for epic MTB rides too!
I hear you and understand what you have in mind. I am of opinion that buying tights with a chamois is impractical since you only ever bring them out during deep winter. Anything warmer and its usually BibShorts with leg warmers.
We do have plans to release long winter tights that work well with The Bibs under them! Using some very special fabrics from our friends over at MITI. Keep a look out!
I don't wear knickers or long tights with chamois built in; I almost always use chamois-less tights over regular shorts. (That lets me mix & match rather than having pricy gear that I only use a few months of the year.)
Lately I've been using the liners from MTB shorts which have thinner fabric so the combo is less bulky, but they rarely have very good chamois.
So my suggestion would be to make liner shorts with a very-high-quality chamois that go well under tights or paired with MTB "baggy" outer shorts. Great for epic MTB rides too!