When should I cash in my EE savings bonds?
This may not really answer your question, but when were the bonds issued?
The reason I ask is that some continue to pay even after maturity and, depending on the rate and any potential upcoming qualifying education cost, you may want to hold on them a bit longer.
Here is a good link to some additional information: https://www.treasurydirect.gov/indiv/research/indepth/ebonds/res_e_bonds_eeratesandterms_eebondsissued051997_042005.htm
Otherwise, in my opinion, if you are no longer earning anything off of these, take the funds and put them to work for you.
Usually, series EE bonds aren't earning much interest so I would recommend that you cash them in whenever you'd like and use that money towards your other financial priorities such as paying down debt, building up savings, or starting a Roth IRA. Good luck!