Can I use per diem for housing ($200) instead of actual costs? Can I use the combined housing/meal per diem ($275) instead, and if so how is *that* entered into Turbotax?

I travel for business for two months each year. Usually I  deduct  actual housing costs and per diem for m&ie.  Last year  housing costs were low.  Can I use the per diem for housing ($200/day) instead of actual housing expenses?  Alternately, can I use the per diem for housing and m&ie ($275/day), and if so, how is that entered into TurboTax, since it combines housing and meal expenses?