I've cycled across that stretch twice. Journals below:
US 50 Nevada:
Bicycling Reno to Salt Lake City, via US 50, "the Loneliest Road"
US 40 Utah:
Salt Lake City to Fort Collins
Both US 50 and US 40:
Epilogue | A bicycle ride across Africa
Largest gap between services is 83 miles between the NV/UT border and 7 miles before Delta UT. In general, I would put NV as a little tougher than UT before Salt Lake as the latter is slightly higher elevation.