That is a lot of brake pad adjustment but, beyond that, will the frame and fork clear the larger diameter tires? Is there enough room under the fork crown and seat stay bridge? I agree that a new set of 26" wheels makes more sense.
Years ago I "roadified" a rigid, hardtail Trek 7000 MTB, converting it to drop bars using an old set of STI brifters, etc. but I kept the OEM 26" wheels.