If you are going to be on or near property, I think the best plan would be to make a reservation for a different park, but make your LLs for MK. That way, at 7:00 a.m., if you book an LL for MK, it will automatically give you a time of 2:00. Same at 11:00 and 1:00 --- you won't be assigned a time any earlier than 2:00.
Two things, though. (1) You would have to get to MK before 3:00, since your first LL will expire at 3:15, even with the grace period.
(2) You will actually need to scan into the first park at some point before hopping to MK, which can be a serious pain the butt depending on your schedule for the morning and early afternoon. Alternatively, if the parks are not at capacity, you might be able to change your park reservation from the other "throw away" reservation to MK, just before heading to MK. I did that one day on a recent trip, and it did not cause me to lose any of my LLs (or ILL$) at MK. But I had a Cast Member at the Disney Guest Services desk at my resort do it for me, so that I could make sure that nothing would go wrong. I wasn't sure that they would be willing to do it. And just because that one Cast Member did it for me doesn't necessarily mean that you might not run into problems from a different Cast Member.