GrimJim:
The following may be something you can use.
In my earlier post I mentioned the bad experience scheduling a trip via Amtrak. The result was that instead of going from Minneapolis to Glacier National Park via Amtrak we did something better by flying. I asked the travel agent to schedule us for the flight and she said OK, but there would be a layover in Seattle. This gave me an idea. We decided to stay in Seattle for a couple of days, then fly on to Glacier.
It cost more than just the flight to Glacier because the flight was technically from Minneapolis to Seattle, then another flight to Glacier , and we had motel and car rental in Seattle, but it was worth the extra money. The extra cost was incrementally more than the price of the whole vacation but we got a lot more out of it.
We have since done other trips like that, where we add a bonus leg to a vacation trip to get more out of the whole vacation.
I never regretted not going by train when I saw what we could do by flying like this.
This June is our 20th anniversary also, and we will be taking a similar kind of trip with a bonus stop like that.
For this sort of thing it does help to go through a travel agent. They are great at arranging the flights, and I have also had them arrange a flight into one city, book a rental car for me, and then arrange the return flight from another city, allowing us to leave the rental car in the second city. This gives us a lot of flexibility and it's well worth the $50 or so that we pay the agent to set it up for us.
One more thing:
Since you're going to Vegas, I recommend flying there because the city is set up for easy air transportation. Then rent a convertible and take a couple of side trips:
1) Go to Hoover dam, about a half hour or 40 minutes from the strip by car.
2) Take your swim trunks to the dam because there's a beach on the way at a park near the marina. It's beautiful water. I don't know how cold it will be in April, but it's worth walking the beach anyway. Take some shoes or flip flops because the beach is gravel mostly.
3) Drive to the NORTH rim of the Grand Canyon. This is a day trip. Try to stay for sunset. It's very beatiful. It is much more beatiful than the more popular south rim. Hang out near the interpretive center at the national park area there. This will take you through the desert near Vegas, past Joshua trees, onto the high desert, through the Kaibab national forest with all its deer (which are a road hazard there), and elk. Take your camera. Plan on heading back to Vegas after dark so you can put the top down on the convertible and let the Mrs. look up at the ultra clear starry night sky. (Bring jackets because it will be cool). On the way to the Canyon stop at the little town where you turn south toward the canyon. There's a little pottery shop there where you can buy a nice gift for the Mrs. The owner is a real right winger so if you get into talking politics you will be there chatting for a while. He's really talented. And he will ship the pitcher or bowl to your house so you don't have to worry about breaking it. The time and money you save by not taking the train can be used for this trip.
4) While at Vegas you must go to Cesars Palace. It's just beatiful in there. Dinner at the Mesa Grill in Cesar's palace is very good. The appetizers are the best things there, but they have an excellent menu otherwise. (Bar drinks in Vegas are very expensive. Try to be a teetotaler there.)