If you need 33 IO pins and the application is const sensitive (and you could use any vanilla 89C51 except the extra IO pin), you can go crazy.
design and nothing else. If you "suddenly" find yourself "needing" one more I/O pin, you have started building befrore the design was complete.

Don't forget, for memory-mapped IO you need to replace the pins you lost for the interface (RD/WR/P0/P2).
If you are not using external meomory, use I/O expanded I/O such as:
for output
2 latches connected to P0 one clocked by P1.0 the other clocked by P1.1
for input
2 "data selectors" connected to P0 one enabled by P1.2, the othe enabled by p1.3

So, now we have lost 12 port pins and gained 16 inputs and 16 outputs for a cost of about $1 (digikey sell "typical" 74HC chips for <$0.25).

Erik