I think it depends on the cancelation policy per property. You should check your booking. If it lets you do full or partial refund, the $135 would probably go back to your CSE.

We booked a 2 night stay in downtown Toronto over this weekend at the Doubletree, and only paid $4 out of pocket. Because of some flight cancelations, we only got to stay the 2nd night (had a family member check in the first night just so we didnt get hit with penalty). When we double checked I saw that we would've been eligible for a partial cancelation 1 day before the reservation date (at 1159pm local time), and full cancelation was 1 week before the checkin date.
Specific thoughts about our stay: We didn't really have any trips to book for this year to use up 2025 credit, or speculative 2026 trips, so I think it was a good option overall. I linked it to my Hilton account and was still able to choose my room at check-in, like all Hilton properties, and got a decent view of Nathan Philips Square / City Hall. Not as nice as the Sheraton but still pretty good. For 2026 credit, I think I'd also use it on a 2 night stay at a mid-tier hotel. Glad that the hotel credit allows for the mid-tier hotel options since you don't have to pay much out of pocket.

Blacklane: Finally used it as well a couple days ago for dropping off at the airport, good if you have a young child and need to book a car with a car seat. We booked the "business class" but did get a larger van which was much more comfortable than a regular sedan. We probably saved $50 compared to the Uber equivalent. The chauffeur showed up about 30mins earlier than the reserved time, but the car seat was not installed very safely (we fixed it ourself), and there wasn't much help once we were at the airport. I think it might be a better service to use when doing pickup from the airport rather than dropoff.