I've found that hotel sales reps will try their best, if it's at all possible, to confirm a late check-out in order to make the sale. Right now, with very low occupancy levels across the hotel industry, a well-situated Virtuoso TA should be able to get you a confirmed 4 p.m. check-out pretty easily.

Late check-outs become difficult in high occupancy situations in which all rooms for the next evening will be occupied. If you think about it, in a sold-out hotel, one guest's 4 p.m. check-out = another guest having to wait until that room has been deep cleaned and prepared for them ... so despite their 3 p.m. guaranteed check-in, they may have to wait 2 or 3 hours for their room.

This, by the way, is why hotels always ask about a client's ETA. If they know a guest will not be arriving until, say, 8 p.m., that opens up a room for late check-out. So if your TA (or the hotel) asks for your ETA, please provide that information! It helps everyone out!