Normally quite OK, however...MEL restrictions might apply.
For example, with the L1011, flights more than 400 NM offshore are not allowed.
In addition, there is normally an MEL time limit on APU unserviceability...ten calendar days in the case of our aircraft.
I noticed several responses to 411A's statement above. Some asked why the L-1011 need the APU for overwater flight: Will it does not.
The L-1011 MMEL has no such restriction.
411A's airline may have added it to their MEL, which is allowed. The airlines MEL can always be more restrictive (never less restrictive) that the MMEL.