After many years, I've finally beat The Minish Cap and Oracle of Seasons.
I played through The Minish Cap on the Wii U, and when I loaded it up, I had an old save file that had just completed the first dungeon, so I just continued from there. I've never really enjoyed the game too much; I think the main quest feels like a slog up until the Temple of Droplets, especially the forced library book fetch quest, then it starts getting fun after that. The last three temples are all excellent. Glad to have finally checked this one off.
When I loaded up Oracle of Seasons on my 3DS for the first time in years, my save file had just completed the SEVENTH dungeon. I don't know why I stopped playing so late in the game. I used a walkthrough to find out where on earth on the last dungeon was, because I had no chance of figuring out where to go on my own, and had completed the final boss within a couple of hours.
Now I'm playing through Oracle of Ages on my 3DS. I started a new save since I wanted to use the code from the end of Seasons, but I never got too far in my original file anyway.
After this, the only main series games I have left to beat are Zelda II and Four Swords Adventures. I own Zelda II on about four different platforms, and I think the furthest I got was about the fourth palace before stopping. I'll probably start again on the Nintendo Switch Online version once I'm done with OoA. I won't get to play FSA for a long time though, because I don't own it, it's super expensive, and I'd most likely be playing alone anyway.