Interesting thread. From what I understand of the OP, he's a currently active CO, correct? Each state has their different rulings on whether a CO is considered LE. In CA., it's basically whether they have powers of arrest (Not specialized powers, but anywhere throughout the state), which certain COs (In CA) don't. It sounds like NYS considers their COs to have it & therefore it'll be on your ID stating that you can CC.
As for going on a trip, you should be fine. Make sure you that you have your ID with you when you carry.
For retired LE, it's a little different. If you're still around your old Dept, you can qualify annually there & be good to go. Again, make sure you carry your ID stating you can CC when you carry. If you live out of state from, or quite a ways away your old Dept, you have 2 choices. Plan an annual trip to your old Dept & qualify or contact the local Dept or SO & see what they can provide for you. Some areas work with retirees in their area & will qualify you for a fee.
Another thing to keep in mind for retirees is that, unless medically retired, they have to have 15 yrs total in LE in order to qualify. If you put in 5, 10, or whatever yrs (Less than 15), you don't qualify. That is unless you're medically retired, then you're fine, provided your Dept. cleared you to CC after they medically retired you.
"HITCH KING", your brother doesn't qualify on 2 accounts. If he did retire & then went to his new job as a fireman, he doesn't have enough yrs & if he didn't actually retire, then he can't on those grounds, too.
Some states obviously handle things differently. "Army Cop" mentions going under the LEOSA & not having to have a CCW. That would be fine in CA, but apparently a CCW might allow you something in another state that the LEOSA doesn't? In CA, I don't think that's the case, but might be elsewhere.
Also, to the OP, where (Or what state) are you going to? I imagine if you're staying in NY, NJ, or another "anti-gun" state, local LE "might" cause you a temporary problem...maybe. BTW, CA would not be considered one of the anti-gun states, at least not for active/retired LE.
Hope that helps.