Server 2012 R2 RDS and QB

Environment:
Box #1
HV1: 2012 R2 hyper-V host
SVR1: hyper-V VM running 2012 R2 is the main server. It's used for file and print and Quickbooks and Lacerte (accounting firm)
SVR1 is replicated to REP1
SVR1 is also continuously backed up to REP1 using ShadowProtect Server

Box #2
REP1: 2012 R2
REP1 replicated to an offsite server for DR purposes
REP1 receives the backups from SVR1 then FTPs them to the same offsite server for DR and ransomeware protections purposes

Problem: Need to be able to allow offsite Win7 and Win10 usage (2-3 users) of QB and Lacerte.

Tried an SSL VPN. Aside from the fact it's not supported, QB couldn't open company files on the server, although full file access through Windows Explorer was fine.

So...RDS seems to be the solution, although I've never used it.
Plenty of RDS installation/configuration info on the web, so that should be a snap.
QB Enterprise is supported with RDS, but client will use QB Pro. I suspect this will not really be a problem.

Where I'm fuzzy...
Ideally I'd think RDS should be installed on REP1 because it's a very low utilization server, however from reading, I get the impression QB Server Manager should be installed on the same server as RDS. Currently QB Server Manager is installed on SVR1 where all the QB files live, and that's not gonna change.

Am I barking up the wrong tree? Do we need an RDS server?

Would appreciate all suggestions.

Thanks
Mark