When calculating the length of antenna elements, remember to use the propagation velocity that is less than "c," the velocity of EM radiation in free space. For a velocity factor, 95% is a fair guess... the exact number of a simple wire escapes me at the moment. Moreover, the velocity of EM radiation in a coaxial cable is much slower, and it is listed for each type of coaxial cable. 66% is a fair guess. This has dramatic importance if one is trying to tune a length of feeder cable... not relevant here, but worth cognizance, just the same.
The OP inquired about using a "longer wire" and I want to introduce caution to that point. Johannes added, with excellence, that the OP really started out with a quarter-wave dipole that uses a phantom second half (the earth, as a mirror) to make a more proper antenna... the half-wave dipole. Proper orientation of the quarter-wave element...the original wire... would be NORMAL and STRAIGHT... i.e, so as to find that mirror (the earth) that it depends on. I do not know how high above the earth this configuration must be; perhaps Johannes can answer that.
More importantly, the half-wave dipole is FORGIVING to neophytes because of its simple "doughnut" (omnidirectional) radiation pattern, at right angles and all around, to the wire(s). In other words, it communicates with other antennas that share a mutual horizontal relationship. There is no gain in the direction of the wire itself... (vertically).
A principal of "reciprocity" says that transmitting and receiving antennas share the same rule book! Well, that is easily taken, in low power situations like this.
If you start using longer dipole antennas, you are instinctively searching for higher "gain." It's not a simple thing! You SHOULD adhere to the rule of using overall lengths that are odd multiples of half wavelength (reduced by velocity factor). If your dipole is symmetric, that's good for novices. Here's the rub: Longer antennas have higher gain... but also have increasingly complex dispersion/reception patterns; iow "lobes." (1 for a simple 1/2 wavelength dipole, 3 for a 3/2 wave dipoole... including both elements of the dipole in this description of length), etc. You must grok these lobes or you're going to be doing some serious scratching of your behind, wondering what is going on. Again, what's good for the transmitter is good for the receiving antenna, too.
Then there are reflections and screens. Keep away from metal objects. Look up (people never look up, ha ha) at any common rooftop television antenna and you'll see one active dipole (horizontally polarized, by the way, typically) and many horizontally-polarized reflective elements... VHF antennas have DIPOLE reflectors in DIFFERENT lengths. When a pigeon sat on THE LONGEST ONE and damaged it, you might recall the loss of "Channel 2" ... if you're old enough to remember that people used to depend on the air waves, rather than cable, for their television viewing.