I'd recommend setting up price alerts on Google Flights for different days and different cities. Sometimes prices drop significantly by just changing your dates slightly. You can also look at prices for the entire month on Google Flights, across many major carriers. You can research the history of prices on your route.
Traveling multi- city is probably your best bet, also called open jaw, altho multi- city prices can be harder to track. But I have found that if I track RT to a specific city, and that price drops, then I check the multi-city rate, it usually drops also.
You have so much time. You could open a new credit card, earn a major miles bonus, and use that to offset the cost. I booked our last British Airways flight going thru the AARP site, ( anyone can join AARP,) which attached a discount ($100 each flight?) but was still booking directly with British Airways. We then paid with the British Airways Visa, which gave us an additional 10% discount. We bought. Business class fares LAX to Amsterdam for $1850 each RT, for next April, 2024.
I feel my time is money, and finding the above fares involved setting up alerts and checking daily, but I got results! I still keep track of the trending costs of our route, and I can tell you the fares are still jumping wildly: going up by double, down by a third, up, and down.
Once you decide on flights, always buy directly from the airlines. Many folks here who have purchased thru third- party vendors end up with big problems if the flights get canceled or delayed. The third- party vendor tells you to contact the airlines, and the airlines tell you to contact the vendor, so avoid at all cost!
Good luck, you have the gift of time!