My daughter (almost 3) is STILL going through this exact stage- I bought her some clothes that were appropriate for sleeping AND wearing out of the house, so on nights before she has to go to childcare, these are the only options in her pj drawer. So she can still choose what she wants to wear to bed, and then we don't fight in the morning about getting dressed. It has worked SO well for us- this started for us in the winter so I bought those $5 fleece tops and bottoms from Children's Place, but now that it's getting warmer, I've replaced them with lighter pants and t shirts/long sleeve shirts. If she asks for her favorite footie pj's, I tell her they are with the dirty laundry.
(Her favorite footie pj's go back in the drawer on weekends and days she doesn't go to childcare.)
Honestly, there's nothing wrong with wearing "clothes" to bed, and our mornings are SOOOOOO much more pleasant!!!