What time do you have to disembark ?

This will depend on the cruise line and the port and arrival time. Most cruises you can get breakfast. Check with the cruise line. Disembarkation is staggered to prevent total chaos. 

On Carnival and Princess, I believe they ask that you vacate your cabin by 8:00 AM.

I do not know what RCCL does, but I would not doubt that they are roughly the same.

By all means, if you don't want to get lost in someones website, call and ask...Ive traveled on 4 different lines, but it all comes down to what YOU feel you have to do...if you're parked nearby, and want to "get a jump", then you "walk off"...with your luggage...usually no breakfast or room service that day, not if you do that, and that's what we do...otherwise you can be assigned a color coded disembarkation ticket, depending on the time you choose..then you can get breakfast, and leave stuff in your cabin...the dailies will tell you when you absolutely positively have to be off....generally, but not always, people who do that let the ships crew take their luggage.., you put it outside your door and it magically disappears during the nite.....course finding it again later is fun...(giant ribbons and bows on the handles helps)...the only variation I found was on Carnival, they do a 'FASTER TO THE FUN" deal, for both embarkation and disembarkation..and it works, but you're on a different line anyway..in sum...its nothing to worry about...call and ask how they do it... 

Agreed. It is nothing to worry about. Every ship I have been on serves breakfast on the last day. Just check your paper for the times and where. Most want you out of the cabin by 8/8:30.

With Carnival, they try to have all passengers disembark by 10:30. Lots of time to get breakfast. No rush unless you deem it so

 Correctomondo..for the life of me I cant remember the "get out, get out NOW"  time...I seem to think it was a bit later than that on NCL...either way, as long as you account for your luggage the nite before, you're good to go...enough peeps stay on till the last minute so you wouldn't be alone getting your bags...I guess theres something to be said for it...but by then we're LOOOONG gone....when its time to go, we go!  (and start thinking about the next one...happens every time)...and we have 4 booked!!!

Many times we have had flight departures late in the afternoon of arrival. We usually have cruise line airport transfers. We like to stay on the ship as long as possible unless they have a good post cruise shore excursion, that we haven't already taken multiple times, to go along with the transfer.

Regardless, I can't ever recall them letting us getting away without vacating our cabins any later than 8:00 or 9:00 AM and then pretty much forcing us to board the transfer coach shortly thereafter. We always laugh, how things chance from how nice they were upon embarkation to how much they are in a hurry to muck your butt off on disembarkation day.