A half-wave dipole for 11 meter is only 17.1 feet long for the antenna to be resonant.. Not much danger of the wire stretching and throwing the SWR off at that length. Now, if you were talking a 160 meter antenna at 260 feet, then you might want to use hard drawn wire, but few hams do. Because they use an antenna tuner than don't care how long the antenna is, and feed it with ladder line with a balanced output on the tuner, or a 4:1 balun.
Also be aware that a half-wave horizontally polarized dipole has a high takeoff angle and is best for NVIS unless you have it at least 34 feet off the ground. If you want lower radiation angle for better long distance propagation, a vertical dipole is better. And for 11 meter it's easy to make one. Here's a video I did on a simple PVC vertical dipole that I built for 11 meter sideband
11 meter Vertical Dipole Antenna - YouTube
The impedance on the vertical dipole is 72 ohm and your transmitter is 50 ohm. So using a 50 ohm feedline you're going to get a 1.44 SWR if the elements are cut for resonance. I was able to tune mine down to 1.3 SWR by shortening the elements excessively, and the center feed should be perpendicular to the antenna for less RF flowing in the shield on the coax. A vertical dipole has 2.19 dBi gain.
This quarter wave elevated ground plane antenna is a much higher performance antenna with better gain than a dipole. And with the radials angled at 30 degrees gives a perfect 1:1 match on the feedline without a tuner
10 Meter Ground Plane Antenna - YouTube