>to make due on savings
Use of Make due:
Make due was commonly used till 1940s; however, it is no longer accepted in English language and using it is considered a grammatical or spelling error.
Examples:
I didn’t have a very high budget so we had to make due with cheap food on the trip.
They will have to make due without internet for a week.
Admit to not knowing the correct and proper spelling myself.
https://www.grammar.com/make_do_vs._make_due