I'll be driving through Oregon without an Oregon carry license. I know (or believe) my WA and FL carry licenses are invalid. (I don't have time now to get a Oregon permit unless it's issued on the spot)

Ideally I can travel armed in some fashion but I suspect not. Can someone succinctly state or link to the Oregon law for transporting firearms.

Second question. I used to have an Oregon carry permit but let it lapse due to huge inconvenience of renewal. Will they issue on the spot or is it a lengthy wait? I am moving to Idaho and would like to get the Oregon permit again if it's not too inconvenient to get it traveling from WA to ID via OR.

If someone might succinctly explain the OR permit process that would be very helpful. THX

This page from Oregon Firearms Federation has an FAQ that hasn't been updated in a while but I would expect OFF to make notes about pertinent changes -- https://www.oregonfirearms.org/faq
The first question/answer should give you most of the info you need. And you're right, OR doesn't recognize any carry permits other than their own.

Under the "CHL Central" heading there are other links to prohibited places, etc., that might also be useful.

In short, OR allows unlicensed open carry. They also allow loaded open carry in a vehicle but do be sure your attire and seating arrangement doesn't leave any gray area between open versus possibly concealed. About a dozen cities/towns have legislated more restrictive laws on loaded carry so you should look at that as you plan your route.

You will probably not find an LE agency willing/able to issue a CHL renewal on the spot so forget about that possibility. Some departments hold open application days about once a month but most operate on an appointment basis. Appointments were running 4+ weeks out for the primary WA resident contact points (Multnomah and Columbia Counties come to mind) the last time I checked.

Open loaded carry will be your best bet but do your research on which cities have restrictions so you don't get any nasty surprises along the way.