Simply remove the width setting, allowing patchwork to automatically determine the width and height.

library(ggplot2)
library(patchwork)

g1 <- ggplot() +
    geom_point(aes(x = sort(rnorm(100)), y = sort(rnorm(100)))) +
    geom_abline(slope = 1, linetype = "dashed") +
    coord_fixed()
g2 <- ggplot() +
    geom_point(aes(x = sort(rnorm(100)), y = 2 * sort(rnorm(100)))) +
    geom_abline(slope = 1, linetype = "dashed") +
    coord_fixed()
(g1 + g2)