I don't think so, partly because the total reward + fees was only 5-6x that of a typical block and partly because almost all blocks are now mined by pools that

I don't think so, partly because the total reward + fees was only 5-6x that of a typical block and partly because almost all blocks are now mined by pools that share block rewards among their members usually based on hash rate, so one would have to be in the pool that mined the block as well. Also the fact that GPUs are less efficient than using specific mining hardware/ASICs for most Proof of Work cryptocurrencies.