We are doing this with Gem Tours (Marlon Diaz)

For me, a night at Tikal is totally worth it! It's wonderful to explore the amazing jungle and massive Maya site during the cooler evening and early morning hours when wildlife is active and you practically have the place to yourselves. Marlon Díaz is a terrific guide - knowledgeable and great company, highly recommended. He could meet you at the border and take you to Yaxhá and to El Portal De Yaxhá for a traditional lunch before heading to Tikal if you wanted. You could do both sunset (for us it was 2:30 to nearly 10pm - we stayed for more than an hour in the Gran Plaza watching shooting stars) or the sunrise tour or both. Yaxhá could be visited on the way back to the border the next day, too, if that fits your plans better. http://ww.gemtrips.com

What about driving to Hopkins? Much closer than Placencia and loved it so much more! It may not look like a big difference but the entire drive down the peninsula to Placencia is full of speed bumps so it takes a long time

Successfully did the walk across the border. We paid extra for “secure parking” on the Belize side—I am not sure it’s necessary but it was $10 USD per night and that seemed like good extra “insurance” for us. It did cause a delay upon return while we tracked down the way to pay and get the gate unlocked for us. We also did Yaxha on the way to Tikal (with Marlon), definitely worth it!

Can you explain more about the secure parking? Who is it run by? The Belize border patrol?

Also, if you return after dark can you drive to your hotel or is it too dark at night out of town?

Oh, sorry for the much delayed response but adding for others.

Yes, when you pull up to the Belize/Guate border, the Belize officers in a booth offer you standard parking or "secure parking" -- which is a bit more. They open a locked chain-link, barbed wire-topped gate and you pull into that secure lot.

We did not arrive back after dark, and I wouldn't generally recommend planning for driving after dark, but you could safely travel a shorter distance back to the hotel. In that case, I'd likely consider planning an extra overnight either on the Guate side or on the Belize side near-ish to the border (and then having the hotel pick you up/drop off). We left our car at the border so that we didn't have to backtrack to the hotel.

Our itinerary was:

Day 1: dep Belize hotel, drive to border, cross and meet guide, Yaxha tour, lunch, to Tikal hotel

Day 2: Tikal sunrise tour (with same guide who met us at Tikal hotel), lunch, nap, back to Tikal for evening self-guided walk, overnight at Tikal hotel

Day 3: dep Tikal hotel with driver, to Belize border, pick up car from lot, travel to Belize coast (stopping for lunch)