I used to do the same, when I had a SPOT. Now I have an in-reach mini. With the plan I have, there are unlimited "canned" text, these are set up on-line. I have a START/STOP, DOING OK and NO CELL/WILL CONTACT LATER. Then you can set up 10 "CUSTOM" ones as well.
I use the unlimited CANNED for MORNING/Start and EVENING/Stop (camping/hotel) like you describe, the no cell is a "still moving check'in". No tracking but all free and I have 2 way TEXT COMMs if they need to get ahold of me. Should I get hurt and no EVE or still moving message, she can send me one and it has the GPS CORDs for body recovery.
I gave up on SPOT, this is better IMO.