Don't quote me, but I think that the Methow is only open above upper Burma Rd. It might be lower. Last year a friend of mine had a great day on the Methow and I went to meet him the following weekend and found that he had been fishing way below the open boundary. Make sure you know the regs. I gave him a ticket, payable by beers at Buddy's in Manson.
The Methow has not fished as well since the fires and the flash floods that dumped tons of sediment in the river. It will take some time to recover.
Worse that that, it has been hot and the river temps are high. A guide friend measured water temps yesterday in the high 60's to low 70's below Carlton. Down by Burma, it is bound to be even warmer. If you do fish, go really early, quit early (by 2 at the latest) and take water temps to see if you should quit earlier. Consider going up higher in the river where the temps should be a bit cooler.
There is not much in the way of stream fishing in the immediate Chelan area. There are, however, some good lakes so you might consider hitting one of them instead of fishing moving water.