No matter what you do to fix it you need to understand exactly what the problem is and why the clutch is slipping before you just wholesale replace the clutch. Since it started slipping after a 275 mile run where you were not near or with the bike you don't know if there were any extenuating circumstances.
At this point I would not
put any more miles on the LT. The more the clutch spins the more contamination will find it's way to the clutch. Of course we are assuming that there is some sort of oil getting on the clutch.
To determine if you have slave cylinder contamination you need to pull the slave and that requires the special socket to put the swing arm back on. I would not do that unless you can borrow or make the tool.
While you are in there inspecting the slave and doing the weep hole drill you can pull the rod see if the rod and the felt pad has fluid on it. If it doesn't then you need to determine if there is engine oil in the clutch housing... There has been at least one member that has drilled an inspection hole. Drilling the inspection hole may give you an idea if you have a seal on the engine side gone bad.
Either one of these two procedures should give you an idea if oil contamination is your problem. If you can't find oil in the housing then you might logically assume that there was significant mistreatment of the clutch and you might try to work it out..
I have read that a few members experienced 'some' slipping and it went away..
doesn't sound good but because you don't know what really happened on those last 300 miles...
Bottom line is the more spins on the clutch without doing something the worse it should get if you have contamination. If the source is the clutch slave and you clean the rod and replace the pad and stop the source it may not get worse.. I have not read of anyone saving their clutch this way but it really comes down to how much fluid is on the friction plate..
I'm sure someone else will add another suggestion. I have not done a clutch but I have read all the posts. That doesn't qualify me as an expert in any way... so maybe someone else will offer more or better advice.