I'm trying to consolidate my wallet since two months now without much success so far.
The concept of consolidating is that it should be done when the fees are relatively low (like between 1-3sats/byte). During periods of price spikes the fees go up and you pay higher to consolidate your funds.
But this doesn't answer my questiin that I thought simple : can I buy a bottle of milk today with BTC ? The answer is simply no unless overpaying it.
If merchants adopt off chain payment networks like LN, it would be possible. For such snall purchases, I would recommend you use cash in your pocket, until bitcoin matures further as a medium of exchange.