It all comes down to what you want at the end of the day. Not trying to plant-shame in the slightest, but under optimal conditions, your plant would be well over the 6' mark at this point in the season.
If you're just looking to have some plants around, learn a bit, and maybe get something tasty - do whatever makes you happy.
If you want to start getting decent produce, you should use a bigger container or go in-ground. A 5-gal bucket with some drainage holes is good bang for the buck, but basically the absolute bare minimum for large indeterminates. If you don't want to make life hard for yourself, switch to a patio-friendly cultivar or aim for a ~20 gal container next year.