I agree that ideally, for long term preservation, it should be brought undercover. However, a tank sitting outside as part of a memorial has a function and a certain attraction. The same sort of debate is ongoing about the
Sherman V at Westkapelle.
Talking from experience (though that is dated), a budget of CAD 250k and volunteer labour should enable a full restoration to running order. A cosmetic / static restoration costs far less as worn out bearings, road wheels, springs, tracks can be (re-)used and engine(s) and other interior components can be left out.