I actually did it, and tried to recreate surviving again, and it's definitely possible, but more difficult. day 1: roll heir +2 generals for siege. If none have siege, restart. If Austria is friendly with Venice, restart. Once you have siege general, day 1 DoW Bosnia and get access from Serbia. march your 2 stack with Skanderbeg towards Donji Kraji alond with your 1 stack with siege general. Walk "past" Donji Kraji to avoid attrition tick with both, have Skanderbeg drop 1 troop, merge with siege guy, leaving Skanderbeg roaming to prevent Bosnia from gathering more troops. Improve relations with Austria, and cancel mil access from Serbia on dec 12. hopefully you have a fort defense guy, if not, no big deal, but may be harder to siege Donji Kraji and Hum. once you have those two, peace out for them and war reparations, and give Ottomans Albania and War Rep, plus ducats. (do not vassalize Bosnia, Hungary or Serbia nearly always declare on them) From there you should be able to royal marry+ ally Austria, and then fabricate on Istria. Attack Venice and with Austria's help, take Istria. From there join HRE and begin anew (I broke alliance with Austria and Allied Poland-Lithuania and France, so when the Ottomans inevitably attacked, I had Austria, France, and Poland on my side. (and this was this Monday)