Hi! It's so great that you're only 7 months into this and already thinking of continuing beyond the first year.
As for your first question, yes, your lo should be taking a fair amout of solids, and yes, your body will adjust to the decrease in milk intake. Now I'm probably not the best example, as I had problems with having too much milk in Lilah's infancy, but I have had no problems keeping up a supply with just two feeds a day. Even if you aren't producing a huge amount, every bit helps. Just don't wean off those mid-day feeds too quickly and you'll be fine.
As for whether your lo will want to continue, that's another issue. Every toddler is different. Some just lose interest earlier on, and unfortunately, there's not much that can be done about that. When your baby is ready to wean, you'll have to follow suit. You could keep pumping and give your milk in a cup if you want to keep offering the antibodies and other health benefits, however. I found though, that though Lilah was more than happy to drop the mid-day feeds in favor of cow's milk in a cup, which she could take outside with her, go for a walk with, etc., there is no replacing the morning and evening feeds. They are sacrosanct. Could be that when the time comes, your lo will strike the same balance.
Good luck! Feel free to ask for our help any time!