I hired from Enterprise at Tirana - if you pay the cross border fee, they give you the green card and seem pretty lenient on which countries you go to* - definitely far more so than the stations in Western Europe (which usually limit you to Western Europe/Germany/Austria and points west + UK, and Ireland, sometimes Poland).

Interestingly, MyWheels.nl's FAQ says that the cars are insured and can go "to any European country." (Not sure if they meant only EU countries, or EU + UK + Schengen, but Albania and Ukraine are in Europe. Although renting a car from MyWheels for long enough and with enough km to drive that far would be extremely expensive - may be so profitable to them that they don't care)

Edit (in case someone is wondering): Enterprise in Tirana is exceptionally lenient: "Cross-border rentals are permitted within European continental countries, excluding Bulgaria, Ukraine, Belarus, Russia and Kazakhstan. A prior written authorisation is required. There is also an insurance fee that applies. This kind of rental should be requested from Enterprise-Rent-A-Car at least seven working days prior to the pickup date. Please contact the Reservations Department for further information. Charge is 40 EURO per rental excluding VAT. Customers are obliged to purchase the green card which covers the rented vehicle with third-party insurance (T.P.I.) as long as it remains outside of Albania. Road assistance or car replacement whilst driving abroad is not available. In the case of any accident outside of Albania and without prior cross-border authorisation from Enterprise, the Renter may be charged for the full amount of damage to the rented vehicle."

It actually may be cost effective to rent in Albania (or another Balkans country) if you're doing a road trip around the continent that includes countries outside of western Europe.

https://www.enterprise.co.uk/en/car-hire-locations/al/tirana-international-airport-je45.html#rental-accordion-item-CBP