I am just reading the paper now but I find this to be quite unlikely to happen Due to the amount of total ADA. I believe the reason staking isn’t currently available is because there aren’t enough nodes yet.
I have read that there is no way that a tx will take longer than the total amount of time in each slot.
Another reason I find your issue not going to happen because you can delegate your stake to a pool kind of like pow pools. This will keep the network robust.
Hope this helps!
Circulating Supply: 31,112,484,646 ADA
Total Supply: 31,112,484,646 ADA
Max Supply: 45,000,000,000 ADA
Edit: please note I may not be correct with all this information but the is information I am currently researching and will provide edits if necessary