Gear Inch / Fire Roads

Hopefully someone can help. Need someone who knows Sherwood Pines well to pitch in

I have a vintage (but mint condition) 92 Raleigh Dyna-Tech Sentinal rigid 26" MTB that I have converted to SS using the big ring and a superstar SS kit, Currently its set up as a 48:18 (70" gear) for my commute on semi slick 2.1 tyres, I have been using this setup for 3 months now, Prior to that I ran a 20t cog at the back (64" gear) but I span out on the flats however I want to pop the 20t cog back on and do some light gravel path stuff.

I am planning on going for a 15-20 mile blast around Sherwood Pines at the weekend, No Single track or XC/off road stuff just basic gravel fire roads / double track. If memory serves its basically flat so no hills to worry about.

Lots of stuff on various forums seem to suggest most SS MTB are running 36:18 etc but I think that would be way to spinny for the flat gravel roads, as mentioned I am not planning on doing any technical stuff or big hills / drops etc

My question is do you think a 48:20t setup will be ok for a steady ride ? Is a 64" gear ok for this sort of stuff or will it be like trying to stir cement

I know its all based on the rider, I would say that I am in pretty good shape and I am well used to riding fairly big geared SS bikes (riding SS on various bikes on daily basis for 2 years now)

Any thoughts from regular Sherwood Pines riders, especially SS riders ?

Thanks