The rules are pretty loose (the width can be anywhere between 46 and 91 metres wide), but in practice real pitches are almost always between 64 and 69m wide and between 102 to 106m long. Even with the loosest possible interpretation of the rules, if you had the biggest legal pitch, you could fit at most 2 legal pitches on it if you subdivided it.

It would actually be really interesting for a team looking for an edge to use an extremely unusual pitch shape to make it hard for visiting teams to adapt.