45min is the MCT for QR to QR unless you are flying to the US.
Remember that Qatar base the majority of their business as a transit and hub operation, Doha airport was built to make transit reasonably simple, and if you end up being late in staff will likely be waiting for you to assist you.

From what has been said above it seems that there is a later connection within a couple of hours so if you miss the connection you can assume you will be put on that later later flight assuming it's not already full.

So if arriving on the next available connecting flight is not a risk you can't take I would book it.