Hi Ptkay,
Being no aerodynamicist, I’m not going to try to answer the question of whether (total) drag might rise proportionately more than lift, except to point out that engine thrust on jets, presumably the Tu-154 included, tends to rise in the denser air.
At risk of stating the obvious, the most common reason for loss of airspeed on the approach in these circumstances is a rapid and considerable loss of headwind associated with the inversion, typically at night over land. This can be predicted and allowed for using the minimum ground-speed technique; given a GS indicator, and provided accurate surface wind readings are available from ATC.
Chris