I think I get your problem, finally! It looks to me like you may want to do some pre-processing of the data before Bubble.
The way I see it, you have 2 lists, previous list (A) and current list (B).
List A holds records for all opportunities last week and list B holds records for all opportunities this week, some of which are new opportunities. List A also holds records of deleted opportunities, insofar as they do not appear on list B.
So a solution would be to merge the sheets, extracting the duplicates, leaving the new and deleted opportunities in separate sheets to work on from Bubble.
If you’re not already familiar with removing duplicates, you may find this helpful:
https://spreadsheetpoint.com/remove-duplicates-in-google-sheets/
Step 1 - Merge Old and New Sheets (Manually)
To create the deleted opportunities list, merge A and B, removing A’s duplicates from B to produce C. So that’s all previous opportunities, including deleted, minus all repeated (duplicate) and new opportunities.
To create the new opportunities list, merge A and B again, removing B’s duplicates from A to produce D. So that’s new opportunities, minus all repeated (duplicate) and deleted opportunities.
You may be able to do this through the sheets API. Requests | Sheets API | Google Developers
Good luck with that!
Step 2 - Bubble
In each case, you could query the remaining data from Bubble (using Sheets API perhaps) defining the range as the entire sheet, A1:Z1000 (as the API ignores empty spaces so the header should remain).
Your reduced list of opportunities may now be small enough to import into Bubble. If not, you can manipulate them with an API.
Does that help?