Jumped in today, forgot how unforgiving ranked is early in a new phase. How long do you Grand Masters or Ultimate Masters need (on average) to get back to your normal MR after a reset?

I enjoyed getting bodied by some Phase 11 Grand Masters in the 1500s, and forgot how rough day one of a new Phase can be.

As someone who's never hit 1700, it made me wonder: How long does it take in a new phase before someone who regularly lands in Grand or Ultimate Master is able to reach their normal peak MR for a Phase?

I suspect (possibly incorrectly) that it takes a little longer for an Ultimate Master to get back to Ultimate Master than it takes me to cross back into High Master, but I wanted to ask people who regularly hit 1700, 1800, 1900 or 2000 in North America (or elsewhere), how long into a phase it tends to be before you feel like MRs are in the range you expect them to be for you and your opponents.