Originally Posted by
lexdevil
In my experience, the Renaissance never upgrades anyone, not even this longstanding PP, from Barlow to Chambers rooms without an extra charge, usually in the neighborhood of £100 per night, though the offer has been known to vary. I do not know if SNAs will change this longstanding policy, but given the tenacity with which the Renaissance has clung to it, I would not expect an upgrade from Barlow to Chambers. I have received upgrades WITHIN the Barlow wing, but the difference between the various Barlow rooms is negligible. If, however, you book a Chambers room, there appears to be a decent chance of an upgrade to a better Chambers room.
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Not 100% true. I was upgraded on a one-night award stay from Barlow to Chambers in December 2017 with no fee without even asking. (I was and am Platinum.)
That being said WRT to the OP, I believe award stays are more likely to get upgraded at all the major chains, but 5 nights is pushing it.