I've gone to Cannon Beach several times from Portland, and I made it there by topping off at the Fred Meyer in Hillsboro before heading west. Unfortunately, using a Level 2 charger to top off can take an hour or more. When I arrive in Cannon Beach, the range meter usually indicates 6 - 8 miles of range remaining.
When traveling near the end of your range limit, be sure to have a back up plan. I usually charge at the J1772 AeroVironment charger at the Cannon Beach RV park, but one time I got there and the Level 2 charger was being used by a Leaf. Fortunately they left within a couple of hours and I was able to get on. If a Spark EV is parked there, they could be on it the entire day! Also, the cell reception in that area is very poor, so if you don't already have a monthly subscription with Aerovironment, making a call to get them to turn on the charger may not be possible. This is worth noting for all remote charging locations. This happened to me at the AeroVironment charger on the way to Timberline Lodge as well. If you don't already have an account and a working card to swipe, making a phone call to the service provider may be difficult. The Spark's Onstar phone works better in these locations, so you may want to buy some minutes for emergencies.
I once plugged in at the Surfsand Resort in Cannon Beach while eating at their restaurant, The Wayfarer Restaurant and Lounge. That charger doesn't show up on plugshare any more, so it may have been removed. You should also have a back up plan for that as well, because someone on their staff unplugged me after an hour, even though I had gotten permission from the manager to stay longer. That's a nasty surprise to come back to if you're counting on having a charge when you return. Thankfully the Spark sent me a text, so I went back to check and still had time to plug in and get back home.
My backup plan whenever going near my limit is to take my portable Level 2 EVSE with me. You can find 240V power in a lot of places, the most handy one being RV camp sites. I learned that little tidbit from a Tesla forum. There are lots of RV parks along the coast, even where there are no chargers. They can all have different plug types, so you will need some adapters as well. But when all else fails, a campsite and a level 2 charger can be your saviors.
Yes, it would be nice if there were more SAE Level 3 chargers on the way out to the coast or other natural areas. As it is, you really have to be committed to making the trip and having a back up plan. Alternatively or additionally, it would be great if you could upgrade the Spark EV to a 6.6kW On Board Charger. That could take 4 hours off of a round trip to the beach. Its the difference between making it a day trip, and making it a very long day trip, or an overnight trip.