I wanted to try this start with Hard AI/AI bonuses to see if it can be done.
First, I can say that in every game out of about 30, the Ottomans attacked with 20k and arrived on November 21st -- even using the tactic described on the previous page.
However, it is possible to fight that initial battle and escape with 4 units intact though it only works around 60% of the time (totally dependent on combat rolls, morale/discipline advisors also improve your odds). What you do is build a merc infantry on day 1, meaning it finishes while the battle in Albania is ongoing, also you need to get military access from Hungary and Austria (Ottomans will often get MA from Hungary and chase you there), and send your cog out to sea. On December 2nd, if your army hasn't been wiped, you're able to retreat (usually you've taken 50% casualties). Manually retreat your main force of 3 led by Skanderbeg all the way to Lika; your merc regiment will have near 0 morale, so you can only shattered retreat it, and this is where the cog comes in -- retreat the merc regiment out to the cog and then by January while it's out at sea its morale will have recovered enough to disembark it in Lika to meet up with your other regiments.
Now, apart from escaping with an intact force, what options do you have? You're going to have to wait several months for your regiments to fully reinforce, and by that point Bosnia has typically built additional regiments so that it now has a force of 8. I tried going for other minors like Urbino, but with Hard AI/AI bonuses, as soon as you declare war the northern Italian countries will hate you and cancel your military access, so you would have to be very careful in microing your diplomats to improve relations enough that they don't do this when the AE penalty hits.
The start that finally worked was a low chance occurrence. The Ottomans had warned Aq Qoyunla, so when AQ declared on Trebizond, the Ottomans were drawn in. They even left the siege of Albania and sent all of their stacks east. I sent around a 1 stack looting all of the western Ottoman provinces so I didn't go bankrupt. During this time, the inevitable Serbia/Bosnia war happened, so I just piled in on Bosnia and made sure to get siege leader on provinces. The Ottomans eventually came back and things got messy, but I ended up with a province in Bosnia and Austria/Poland as allies, then a war against Venice got me Ragusa/Dalmatia and I moved capital to join the HRE.
I was gonna try my theory for this... Declare on Venice. Offer vassalisation (i think venice might accept that, yes?).
Then ask support independance from Austria, france etc, while venice is at war with ottomans since they vassalised you while you were at war with ottomans. Funny thing is that venice in this situation can call in all their allies...
See where i'm going with this?
This ofc depends on who is enemy/rival of venice. I doubt there is other country that might accept Albania as a vassal..
Heck, maybe offering you as a vassal to ottomans might work if ottomans start with rival Austria and aragon etc.
Didn't have chance yet to test if this works.
I tried declaring war on pretty much everyone around to see who would accept vassalage as a peace offer, and thereby draw them into war with the Ottomans. Sometimes, maybe around 25-30% of the time, Byzantium or Aragon will have the Domineering attitude (iron gauntlet icon next to relations) and only in this circumstance will they accept vassalage if you declare on them. Problem is, neither country can beat the Ottomans on land (Aragon destroyed the Ottoman navy and blockaded, but made no effort to land troops -- probably a good idea considering their odds). And eventually the warscore ticks from Albania's occupation will mean that the Ottomans have enough to take stuff and both of your potential overlords are fully willing to give away Albania -- game over.
Anyone who starts as hostile will want full annexation (Venice/Ottomans), and anyone neutral will refuse to accept you as a vassal.