Muti-currency Debit Cards in US?

Sounds like a pricey proposition. These pre-loaded cash cards have lots of hidden fees. If you want to engage in currency speculation, talk to a stock broker or one of those on-line Forex markets. That is is essentially what you are doing. How do you know that the USD will not increase in value as US interest rates rise and cause capital flows to come into the US? If I am in the import/export business with big money volumes at stake, I would. But for an individual trip, its just that, currency speculation.

Your trip is long ways away. A lot can happen 17 months from now.
There is no guarantee that one would save money buying euros that far in advance

Instead of speculating on where the currency is going to move, just stick with the old true-and-tried ATM (debit card tied to a checking account) to withdraw cash. It's the easiest option and will get you the best exchange rate. Those preloaded cards are not a good idea for many reasons (exchange rate, lack of acceptance, etc).

Very few series 7 licensed stock brokers will also hold a series 34 Forex license. So talking to a stockbroker about currency trading will be out of their realm of expertise and their broker/dealer licensing. If you are not licensed you can’t talk about a product.

Sure, all kinds of pre-loaded cards are available. No different than in Europe. Many banks, Travel-ex, AAA, credit unions, even Wal-Mart will be happy to sell you a pre-loaded card. And I think you can buy them via the internet, load them with any amount that you like. Stick with either a VISA or Mastercard branding. These cards generally come with lots of fees - some disclosed and others hidden. Historically these cards have not been considered a good deal because fees often range from 6 to 12%. Also these cards are classified as gift cards by banking regulation so you do not have the same degree of protection that credit and debit cards have. But if you don't have access to a debit cards then these cards are about you only option. I assume you cannot get a debit card so you are pursuing this option. It is OK but not great.

I'd guess there is a monthly maintenance fee(?) that might more than wipe out any gain you might get with rising currency rates in the next year.

Just join a credit union that offers a 1% currency conversion fee for ATM withdraws and no per-use fee. Andrews Federal Credit Union (based in Maryland, but you don't have to live there) charges 0%. $5 to join the American Consumer Council to make yourself eligible to join Andrews.

Keep in mind that "buying" currency always comes with a cost. Usually that cost will offset, or worse, any savings you might luck out on with changes in rates.

If you want to be proactive, open an account with a debit card that does not charge foreign transaction fees for ATM withdrawls or purchases. Those can add up between 3-6% from many banks. That will save you far more (and not even that much) than currency speculation.

How do you know with certainty "when he exchange rates are favorable"?

Who knows what the American president will do next or what will happen in Italy?
https://www.express.co.uk/news/world/929923/Euro-Brussels-Italian-election-latest-Donald-Trump-trade-war

Euro in DECLINE: Brussels fears for currency over Italian election and Trump trade war

BRUSSELS finance chiefs are panicking that the
Euro could be facing a rapid decline due to the twin threats of the
surge in support for Eurosceptic parties at the Italian election
result and a trade war with the US under Donald Trump.

Good example but it is very important when quoting or reading British papers to understand the political agendas at play.

I personally give little credence to any of the Red-Tops (sensationalist) of either political stripe, and unfortunately never anything written in the Daily or Sunday Express. They shriek and panic - and exaggerate - like Fox or the National Examiner.

Have a look at some of the other headlines at the top of the linked webpage....

It certainly is true that if any of us were any good at making profit in foreign exchange we wouldn't likely be writing here....

Unless you have no choice which forces you into these cards I advise thinking again.

There are two separate things. One is you believe you can profit from fluctuations in currency valuations. The other is you want the cheapest, most frictionless way to have money on your trip.

These are not at all related.

For currency speculation, you have several options. One of the easiest is to buy shares in in a mutual fund or funds, or ETF, that is invested in non-dollar-denominated securities. Note however that some foreign stock and bond fund are hedged to compensate for currency fluctuations--exactly the thing you hope to take advantage of. So invest in the unhedged funds.

Meanwhile, on the ground in Europe, locate a bank that does not charge fees for foreign ATM use and a credit card that similarly charges no fees for use overseas, and use them.

Another thing to keep in mind is that what if you aren't able to go in 2019? Then you'll be stuck with a bunch of useless Euros. A job change, family or medical emergency, or just a change in plans can happen in the next 18 months. Or, you may just change your mind and decide to go someplace else where the Euro isn't used.