We have stayed in a couple of different hotels in Moses while fishing at Potholes. Mardon and the state park do not compare as far as comfort or amenities. I will never stay at Mardon again.
We stayed at the Shilo Inn at the intersection of 17 and I-90 a couple of times. Decent parking for trailers, ok rooms, pool. As far as charging, you might get lucky or you might not. You will have to try to get a room near where you park the boat and run a cord outside to the boat. That doesnt always work out. We didnt see any outlets to plug into outside that we could get to. The other good thing about that general area is Bobs Cafe in on the same lot. Great place for an early bfast you can walk to from your room.
We also stayed at the Travel Lodge on S Pioneer way in Moses lake. Not as nice but still ok rooms if your just a bunch of guys on a fishing trip, worse parking because you ahve to park in a lot behind the hotel, so its harder to keep tabs on the boat. The parking lot is also harder to get into when there is traffic. Cheaper rates though. We didnt even try to charge there, the boat was parked too far away.
Next time we are going back to Shilo.
There are some really nice places to eat dinner in Moses though. We especially like The Porterhouse Steak house, Michaels On The Lake, and El Rodeo. El Rodeo is the least $ but very good mex with large portions. Micheals is more top end and $$$ but very good food and right on the water. Porterhouse has first class steaks and drinks for in between $$.