As seen here, the equation for lift involves the lift coefficient Cl, the density, $\rho$, the velocity, $V$, and the wing area $A$ in this equation: $ L =C_l\frac{\rho V^2}{2}A$.
The key thing for your consideration is that there are a few design variables we could play with to try to maintain lift. If density ($\rho$) is decreased, other variables must increase proportionally to keep lift a constant. The $C_l$ term can be increased to an extent to provide more lift but there are drawbacks. Velocity($V$) is nicer to increase, since it has he squared relation. It only needs to be increased by a square root factor. (If the density is halved, the velocity needs to be increased $\sqrt{2}$ times). Lastly, we can increase the wing area. Super simple, right?
Wrong. Unfortunately, these design variables have other effects that aren't immediately noticed. 568
Increasing the area often means more weight and/or drag. Velocity increases often require larger powerplants, and Cls can be picky in their performance across your flight envelope.
That all said, its totally possible to design for and fly in low density, there are just a few things to really look into.
As to the specifics of Jet Bis, Tris, and Quadplanes, I don't know. A lot of high altitude (thats low density on earth) aircraft have very high aspect ratio wings (quick google search). From what I understand much of the reasoning behind bis, tris and anything above, was that the materials available didn't support the necessary structure, at least not easily. So, to get around long, broken wings, they added multiple shorter wings (still getting the same wing area) that the materials (wood, wire, canvas) and the structure (wire box frames) could support. They did have plenty of drawbacks. Those structures with all those wires added a ton of drag. Stronger materials like aluminum came into phase because they could support the wing, without the exposed "draggy" wireframe structure. In, my mind, If you have the tech for jet engines, likely you have tech for long single wing structures.
Check out this Aviation SE post about biplanes. 308