The deadline
I have Snapchat+. Does the limit affect me?
No, not as long as the subscription is running and you stay under your tier. Snapchat+ raises the ceiling to 250 GB. But the limit does not disappear, it moves, and if you stop paying you have 48 hours before anything above 5 GB is deleted.
Short answer: you are safe while you are paying. The 5 GB storage limit applies to accounts without paid storage. With Snapchat+ your ceiling is 250 GB instead, and as long as you are under it nothing happens to your Memories.
Snap has three tiers: 100 GB, 250 GB with Snapchat+ and 5 TB with Snapchat Platinum. If you are using, say, 60 GB out of 250 GB, you are nowhere near your ceiling, and nothing you have saved is at risk for as long as the subscription runs.
But the limit is not gone, it has moved. That is the difference from having the memories on your own drive, and it only becomes visible the day the subscription does not renew. Snapchat says you then have 48 hours to sign up again before anything above 5 GB is deleted. An expired card, a change of phone or an ended family plan is enough.
Forty-eight hours is short. It is shorter than a holiday week without mobile coverage, and shorter than the time it takes to notice a bounced payment. We do not say that to frighten anyone, but because it is the only practical difference between renting your storage and owning it.
There is no conflict between the options. Plenty of people keep Snapchat+ because they like the features, and still get the export out once so the memories sit in their own photo library. Then it makes no difference what happens to the subscription later.
If you want to see what your own number means, with the tier it would require and how large the export gets, there is a calculation per size here: sparaminamemories.se/en/snapchat-lagring