"I assume that we're heading to the wall to climb over?" Loras stays with the group even if they opt to go through the gate but if they opt for an unpatrolled section of wall he clambers up as carefully and quietly as he can, stopping when a guard moves by until they are out of earshot.

Spoiler
Show
Hide (1d20+9)[27]
Move silently (1d20+10)[18]
Spot (1d20+1)[5]
Listen (1d20+5)[6]
Climb (1d20+12)[18] Including taking 10 on the climb check.

If anyone gives him a rope then he will carry it up and pass it down to the less nimble party members after securing it.

Use rope (1d20+3)[10]