Is 30 min to an hr driving our car to the parks, since there is no other way to get there since we're not going to be staying on site this time? I've told myself I'm not going to do bag check this time. Have always wanted to skip that.
If you're driving between the parks, I can't imagine the actual drive taking more than 20 minutes between any two parks. We always drive when we go to Disney, and it's rare that we've taken more than 10-15 minutes between parks. But then, we go at historically "quieter" times than June, so maybe the traffic has an impact in the higher season - I'm sure if someone else has personal experience, they'll chime in.
In short, it doesn't take long, once you're in the car, to hop between parks. The extra time comes in waiting for a tram/walking to your car out in the lot, dealing with the TTC outside Magic Kingdom, parking in the new lot, and then walking up to the next park's gates. Not a hideously long time, but definitely enough to make a difference in your day, I'd say. You can't just decide back by Muppets 3D in Hollywood Studios that it's time to move on to the next park and expect to reach let's say Animal Kingdom in 20 minutes from that point.
That said, it's totally do-able to hit a few highlights in all 4 parks in a single day. I know I've seen other threads here from people who've done it. Choose a top-priority ride or two, maybe a snack location you must hit, etc, for each park. You can start and end in whatever parks you like best, but to maximize your time, and since you said you want to end in MK (for Wishes, I assume?), I took a look at easywdw's crowd calendar/park recommendations for June 28th. He's got EPCOT listed as the not-recommended park, so that's actually where you probably want to start - early, at 9am rope-drop, hit the things you most want to hit there before the park fills with crowds. From there, you can choose equally, I'd say, between Animal Kingdom and Hollywood Studios. Either of those would be a good place to book your FastPasses for the day - if you want to ride the headliners (Toy Story Midway Mania, Tower of Terror, etc) at Hollywood Studios, that's where I'd use them, if I were you. Once you've done your must-dos at those parks, head over to MK for the night. It's the most-recommended park, though granted, it's a busy day overall, crowd level 8 out of 10. You can finish your evening with the Celebrate the Memories and Wishes at MK, which sounds lovely and romantic for an anniversary.
By starting at EPCOT and ending at MK, you do have the option of leaving your car parked in a single lot and using the Disney buses to get around, if that's something you'd prefer. (I'd rather drive and not have to worry about waiting for a bus on a busy day, but lots of people love the Disney buses - totally up to your preference). Just take the monorail from the TTC to EPCOT and your car at the end of the day, or park at the TTC early in the morning and monorail to EPCOT before rope drop, so your car's closer to where you finish your day.
If you want a sit-down meal at some point, pick which meal/park/restaurant ASAP and try to get a dining reservation for that day immediately. You may have to make a short list of choices to get one you really want at a time that's convenient, based on what order you choose for the parks. If you're happy to just fuel up on snacks and quick service stuff, then don't sweat it, just munch as you go.
You absolutely can do this, and I hope you have a fantastic time!
ETA: the reason I didn't recommend wrapping up at EPCOT is because it actually closes at 9pm, with EMH running until 11pm. Obviously, that's a perk for onsite guests only, so the extended time isn't helpful in your situation. And the park is likely to be very crowded because of those evening EMHs. Plus, you said you wanted to end at MK.
Why would they block me out if I get to MK when they open? I guess I'm maybe thinking of park capacity as well. How far in advance would I know?
Congratulations We've never been by ourselves. That's our goal is to go some without the kids and some in the future with grandkids.
