Airport Hotel or Not?

This hotel is right at the airport and should work if you decide to play it safe with the morning departure -- which is what I would do. Trim looks to be at least an half-hour drive from the airport, more if you're not lucky. If you're on a nonstop, I believe you go through US immigration and customs processing at the Dublin Airport, which will be very nice when you get home but add some time before your flight. Plus dropping the car, plus any bag-checking, plus security. That adds up to a very early wakeup if you're in Trim, but less early and less uncertain if you're at or near the airport the night before.

I've stayed at the Carlton Hotel Dublin Airport. Nice hotel with shuttle service to the airport.

I also had an early flight but to the UK.

I've stayed at the premier inn just a few moments on the shuttle away from Dublin airport. It was reasonably priced, clean, and a scheduled shuttle make regular airport runs that got us there in 5 minutes. I strongly suggest not trying to make a flight from out of town on the same day. So many things can go wrong.

I'd definitely stay in Trim and make the drive early the next morning. I've done this twice from Drogheda and once from Howth. To me, it's worth the trouble to stay an extra night at a place like Trim rather than the airport. The last night is often a memorable one. The drop off never takes long and it may even be early enough that they're not open and you just drop the keys in the night box. Just add a bit of time to compensate for morning traffic.

If we stay in Trim the last night, how early should we leave to have an abundance of time to make our flight? We will probably rent from Eurocar. Is there a problem with early morning drop off?

Look up the drive with Google Maps and factor in 20-30 minutes extra just in case. You can get Europcar's hours. But, whether they're open or not factor another 30 minutes for that.

google maps has an estimate of 45 minutes on a weekday morning from Trim to DUB. I have found google to be optimistic in their estimates. Adding time to re-fuel, check in the car and get the airport proper, looks like a 4AM wake up.

I would be inclined to drop off the car the night before as late as possible and be at hotel at/near the airport. That way you can spend all of your 'day' in Trim and sleep close to the airport, for a stress free night

My $0.02

I'd lose sleep the night before getaway day if I had to deal with the unnecessary complication of getting to the airport early to turn in my rental car - too many things that could go wrong ... from traffic delays to unforeseen issues returning the vehicle. Departure day is usually stressful enough - why overly complicate things?
The Premier Inn at the airport is a good suggestion.

Hello from Ireland,
Don't kid yourself. Get yourself to the airport. Late in the day as you can and still return the car. Don't try to drive to the airport and return a car and clear all the hoops to get on board your plane by 10:15. The customer ahead of you at the car rental could be returning a car with damage and settling that could take an hour. A flat tire could derail everything. A car accident that blocks your path....

My wife and I learned some years ago that the last night is spent in a bed at the airport. Or we book mid to late afternoon departures. And, if possible, a room within easy walking distance of the airport. Shuttles can get funky too.

Trim is nice, a tour of the castle and one evening exhausts it.

wayne iNWI

This is a copy of our reply to a similar question back in the pre-Covid days. We were nervous about driving back to Dublin, turning in the car, airport check-in, etc. The HI Express worked well for us. I assume it's still reliable adivce:

"We were satisfied with the Holiday Inn Express. Somewhat spartan, but we thought is was a good value.
Nice little Italian restaurant around the corner.
There's a HI Crowne Plaza next door; more amenities, I assume. They share a reliable shuttle from/to the terminals."