Early flight Vienna - Paris (6:20am) or Amsterdam (7am) to USA

I would go with Amsterdam, as I find it much easier to maneuver my way through on a layover than Paris. Also, you'll be going from Schengen to non-Schengen, so you won't have to go through security but will need to go through passport/immigration. That said, the lines there go relatively quickly (unlike Paris).

Plus since you only have a 60-minute layover, you can show them your boarding pass and they will bump you to the line in front where you'll go through ahead of the others. Basically, you should be fine with a 60-minute layover.

As far as arrival time, I would get there 1 1/2 to 2 hours ahead of time just to be safe, but that's me.

Both options aren’t great. If your plane from Vienna is delayed, it will be stressful. We had a similar situation last summer, flying from Milan with a short layover in Schiphol. Though our flight from Milan was delayed, we still made our flight to the US. Same scenario happened to us about 5 years ago with Paris as our layover airport, and that worked out okay, but we had to sprint through the airport. I’m glad we had checked our bags because carry-ons would have slowed us down. It is a tough call. If the layover time was the same for both airports, I would definitely choose Schiphol. I assume you purchased all legs on the same ticket? We took an uber to the airport in Vienna.

I agree with Melanie that it's stressful if your flight is delayed, but that could happen no matter how much time you have. Since you're on one ticket (I'm assuming), the airline is responsible for getting you to your final destination regardless. I still think AMS is the better option.

Are these Air France or KLM flights? KLM is wonderful about getting people that are stuck to their next destination. I had a flight canceled when I was taxiing in to AMS two years ago, and as soon as I got to the gate, I went up to a KLM agent, and within 15 minutes she had me rescheduled and booked on another flight.

Amsterdam is definitely the better airport for short connections.

When I am faced with such a choice, I also consider which city I would rather be stuck in (e.g., would you rather spend the night in Amsterdam or Paris).

In Vienna you can just call (by phone) a taxi, but you need to mention that you want an airport transfer (flat fare instead by meter). They should tell you the fare upfront.

Usually people book a taxi in advance. There are several companies specialized in airport transfers. The fare should be around €45.

Is it possible to fly from Vienna to Amsterdam the afternoon or evening before?

I've done the "flight at 6A" to an international European hub and decided after the last one (Italy to Amsterdam to US) that I would not do that again.

IF you have to choose one of these routes, I also vote for Amsterdam. 90 minutes is not enough in Paris.

When I traveled home from Europe during my business career I never took a morning connection. All too often I would be at the Frankfurt Admirals club waiting for a colleague whose morning connection was delayed. I got home today. They got home tomorrow. As others have suggested, fly to Amsterdam late the day before and spend the night in an airport hotel.

Now that I travel mostly by train while in Europe, I follow the same basic strategy to be at an airport hotel the evening before my flight back to the US. So much less stress when you can see the airport terminal from your hotel room.

Just to clarify:

The flight via Paris is with Air France.
The flight via Amsterdam is with KLM.
Based on your unanimous advice, I’ve decided to go with the Amsterdam option 😊 The flight departs at 7:00 AM, which feels much more manageable.

My only remaining question is about the connection at Schiphol. For US-bound flights, are the gates typically far from the Schengen arrival area? And will I need to go through passport control and/or additional security before boarding the flight to Houston?
Thanks again for all your guidance!
Found this link related to transfers at AMS https://www.schiphol.nl/en/transfers/

My only remaining question is about the connection at Schiphol. For
US-bound flights, are the gates typically far from the Schengen
arrival area? And will I need to go through passport control and/or
additional security before boarding the flight to Houston? Thanks
again for all your guidance! Found this link related to transfers at
AMS https://www.schiphol.nl/en/transfers/

You can use that web page to see where the flights you selected typically arrive and depart to sort out how far it will be. Remember the landing time of the flight is not when you're walking off the airplane, so you'll have less than 60 minutes to start with.

There is a short connection lane at security at Schiphol, but you must pay attention and may need to ask for assistance. And there will very likely be extra steps for your Houston bound flight (last time I flew out there was a second passport check). They will very likely already be in the boarding process as you are landing from Vienna, so I would also verify what time they close boarding the aircraft (usually 15 minutes ahead of the flight but sometimes it is earlier). With some magic and fast footwork, you could make it, but it will be a very, very tight connection. If there is not another Houston bound flight that day, you will quite likely be staying overnight (at a minimum).

In that situation I too would fly to AMS the night before and stay at an airport hotel. You'd save a night hotel cost in Vienna, save the cost of early morning taxi ride, and make your morning flight with minimal stress. It's possible to book flights with a long overnight layover, it might just take a bit of finagling on the airline website to find them. Then you're all on one ticket.

Well, that does not sound good at all. Why would KLM sell this route and risk covering our hotels etc. if we miss the flight (it is on one ticket). In any case thank you for all the good info.

Why would KLM sell this route and risk covering our hotels etc. if we miss the flight (it is on one ticket)

Because with rare exception it works just fine. If it didn't it would get expensive for them and they would stop selling it.

Just don't be bashful about saying "I have a tight connection" .

I've taken early morning flights from Vienna--although not that early.

What I did was stay at a hotel directly across the street from the terminal rather than travel in from the city. It gave me a little extra sleep.

And will I need to go through passport control and/or additional security before boarding the flight to Houston?

ershirbeg, I answered that question above, but you may not have seen it. You will need to go through passport control, but you do not need to go through security again. The line for passport control usually proceeds pretty quickly, but given that you have a quick connection, just show your boarding pass to an employee. They will pull you from the line and take you to another line up front that is strictly for people that have a quick connection. They are really good about that, so I would not worry about it too much.

And as Frank II mentioned, I would definitely try and find an airport hotel for the night before. It makes getting over there in the morning so much easier and less stressful, and I love having that extra sleep time. I do that anytime I have a flight before noon.

I've taken early morning flights from Vienna--although not that early.

What I did was stay at a hotel directly across the street from the
terminal rather than travel in from the city. It gave me a little
extra sleep.

What hotel did you stay, if I may ask?

I would go with Amsterdam, as I find it much easier to maneuver my way
through on a layover than Paris. Also, you'll be going from Schengen
to non-Schengen, so you won't have to go through security but will
need to go through passport/immigration.

Caveat. You TYPICALLY do not have to go through security. Many don't know that the Amsterdam airport does random security checks on people going Schengen to non-Schengen. There are generally 1-2 airport/security employees stationed at the exit from passport control eyeing passengers exiting immigration. They let most passengers continue their path straight ahead to go to the gates, but they select some to detour to the right where scanners and security are.

I've learned that being a good Southerner, making eye contact, smiling, and saying "Hi" increases the likelihood of selection. Avoid eye contact and keep moving!

Caveat. You TYPICALLY do not have to go through security. Many don't know that the Amsterdam airport does random security checks on people going Schengen to non-Schengen.

Dave, that can happen at any major airport, so I don't typically include anomalies when I am giving someone advice about Schiphol airport. I definitely would not consider that a factor in whether to choose AMS or CDG. 😊