There were numerous biplanes vs biplanes battles over Egypt, Libya and East Africa in late 1940. So this Winter War battle was far from being one of the last.
Later at the start of Barbarossa both sides used biplanes (Finnish, Slovak and Hungarian on the Axis side).
AFAIK the last biplane vs biplane battle was on 4 October 1942 and saw both sides (Finnish and Soviet) using the same aircraft, I-153.
See
http://surfcity.kund.dalnet.se/polikarpov_finland.htm
By the way, the above site is the reference for biplanes in WWII.